Koichi Kimura (木村 輝一 Kimura Kōichi?) is one of the protagonists in the Digimon anime series Digimon Frontier. He is one of the "DigiDestined", children who were chosen to receive the ability to transform into Digimon in order to save the Digital World, and he is also known as one of the Legendary Warriors, inheritors of the Spirits of the Ten Legendary Warriors. He was originally brainwashed by the fallen Cherubimon to serve as one of his evil Warriors.

Koichi's first appearance is that of the antagonist Duskmon, wielder of the Spirits of Darkness and one of Cherubimon's servants. Once freed of this control, he fights alongside the DigiDestined. He is Koji Minamoto's older twin brother, having been separated by their divorced parents at a young enough age that they grew up unaware of each other.


Koichi is a young boy with pale skin, short black hair that is parted to the sides of his face, and dark blue eyes. He wears a red long-sleeved shirt under a green open button-up shirt with short sleeves, white pants, and green sneakers with yellow streaks. He wears a blue cap with a white symbol on the front in the Human World, but he loses it upon his transition into the Digital World. His face is identical to his twin brother, Koji.


Koichi is a reserved boy with a kind heart who wants to do the right thing but is prone to burying his problems in his heart. Within him, however, is also a great potential for darkness, born from his resentment of his twin. Cherubimon uses this darkness to great effect, but Koichi overcomes his weakness through his love for his brother.

As Duskmon, he is cold and aloof. He doesn't interact with the other members of his team, who can at the very least work together toward a shared goal, and he sees only the value that they can bring as fighters. He is also single-minded loyal to Cherubimon, though much of that is due to Cherubimon's influence.


Kōichi Kimura (木村 輝一)

Name used in the Japanese version of Digimon Frontier and related materials.

  • Ja: Kimura (木村?). Japanese surname that means "wood village". Possibly a reference to the kimura-gumo, as spiders are part of goth subculture, and Koichi is the wielder of the Spirits of Darkness.
  • Ja: Koichi (輝一 Kōichi?). Japanese male name composed of the kanji for "radiance" (?) and "one" (?). "輝" is likely a reference Koji, wielder of the Spirits of Light, while "一" likely refers to the fact he is a first-born. Revealed Past! Duskmon's Secret
Koichi Kimura

Name used in the American English dub of Digimon Frontier and related materials.

  • Koichi. Anglicized form of "Kōichi".


Koichi is Koji Minamoto's twin brother and the elder of the twins. Their parents divorced when they were very young, and neither twin could remember the other. His mother never told him about his brother, and Koichi only learned about Koji when his grandmother told him on her deathbed. Koichi, feeling that his mother had enough to worry about, didn't inform her of his new knowledge.

List of Digimon Frontier episodes 22

Koichi attempting but unable to talk to Koji.

Koichi eventually managed to track down his brother and started to periodically watch Koji and his family. He yearned to meet his newfound brother but was never able to bring himself to interrupt the seemingly happy family. Over time, deep in his heart, Koichi began to grow bitter that their father had abandoned him and their mother, whom Koichi worried for due to the strain being a single parent.

On the same day that the rest of the DigiDestined enter the Digital World at Shibuya Station, Koichi decides to meet Koji and follows him to the train station, unknowingly crossing paths with Takuya Kanbara. After just missing the same elevator that Takuya himself only barely made, Koichi finds himself running to catch up with Koji, but he loses his footing and falls down a flight of stairs, collapsing as a result.

Koichi is taken to an isolated sector in the Digital World where he meets Cherubimon. Cherubimon, sensing the sadness and darkness residing in his heart, entices him to join his cause. He erases Koichi's memories and suppresses his personality by giving him the corrupted H Spirit of Darkness. As a result, Koichi becomes Duskmon, the Legendary Warrior of Darkness. Duskmon joins Cherubimon's corrupted Warriors as a distant, aloof ally, never really interacting with the others. Ne'er The Twins Shall Meet

4-30 Koichi's Corruption

Koichi seduced by Cherubimon into becoming Duskmon.

After Grumblemon loses his Beast Spirit to the DigiDestined, Duskmon is the only member of the evil Warriors to refrain from the assault on Seraphimon's Castle at the Forest Terminal. Better An Egg Than An Egg Shell He stays out of most of the subsequent battles until a conversation with Mercurymon in which he calls into question Mercurymon's loyalty while Mercurymon calls him a coward for avoiding conflict. Duskmon, considering the DigiDestined an annoyance, decides that a battle would not be outside of his capabilities and proceeds to the Continent of Darkness. Duskmon arrives in time to see Arbormon lose his Beast Spirit. Seeing him as a liability, he dispatches his fellow Warrior. From Dawn To Duskmon Duskmon engages the DigiDestined twice in the Forest of the Continent of Darkness. The first time, he takes all of the DigiDestined's attacks without flinching, with the DigiDestined only fleeing after BurningGreymon engulfs him in fire. The second time, he continues to be deeply disappointed with the DigiDestined's strength and attempts to strike down Agunimon. KendoGarurumon takes the blow for him, reverting back to Koji in the process. As Agunimon screams Koji's name in anguish, the word resounds in Duskmon's consciousness and brings him pain, causing Duskmon to paint the entire area in darkness as he retreats to regroup. Darkest Before Duskmon

Desiring answers as to why Koji can affect him so, Duskmon enters Sakkakumon's Darkness Area and accosts him by sifting through his memories. Duskmon begins to doubt himself, making Cherubimon reinforce his hold over his Warrior. Duskmon and Koji clash, and though Duskmon comes out the winner, he is interrupted by Seraphimon's Digi-Egg before the finishing blow. Koji becomes BeoWolfmon, and the Warriors of Darkness and Light clash again, more evenly matched. With their souls bared in their blades, BeoWolfmon manages to get a glimpse of Duskmon's true form, right before their battle forces Sakkakumon to eject them from his body. Stuck In Sakkakumon With You Duskmon and BeoWolfmon proceed to have a running battle in the area around Sakkakumon, which BeoWolfmon eventually wins until Cherubimon personally intervenes. Duskmon continues to doubt himself, attempting to find out why BeoWolfmon invokes such emotions in him, so Cherubimon again cements his control over the Warrior of Darkness by reminding him of the day he came to the Digital World as well as the resentment involved. He then gives Duskmon the B Spirit of Darkness which enables him to become Velgemon. Velgemon sacrifices Duskmon's rational thought for immense power and an obsession with Koji's destruction. He nearly succeeds in his goal until Ophanimon intervenes through Koji's D-Tector, reviving Velgemon's suppressed memories. Velgemon once again flees to center himself. O, Brother, Who Art Thou?

List of Digimon Frontier episodes 33

Koichi's reawakening as the true Warrior of Darkness.

Returning to his Duskmon form to regain his rationality, Duskmon again questions himself. This time, rather than wipe his memories, Cherubimon preys on Koichi's love for his mother to inflame his hatred. He gets into one final clash Koji, but the combined forces of both Koji and Takuya prove to be too much for even Velgemon's strength, and Koichi is defeated, the Spirit of Darkness taken from him. My Brother In Spirit Now free of Cherubimon's influence, Koichi is wracked with guilt over his actions. He explains the events that brought him to the Digital World to the others and travels with them, though he remains distant and reticent. When Cherubimon attacks the Trailmon they are riding on, Cherubimon tries to win Koichi back to his side by playing on his inner darkness once more. Koichi has moved beyond that, though, and flat out refuses. Cherubimon moves to kill his old servant, but Koichi's conviction merges with the light from Koji's D-Tector to grant him the power to spirit evolve using the newly purified Spirits of Darkness. Becoming Loweemon and JagerLoweemon, he manages to defeat his old master, revealed to be just a shade of the true Digimon. Filled with a desire to atone, Koichi attempts to continue alone, only to be rebuffed and joined by the other DigiDestined, who want to see their journey to its conclusion. Ne'er The Twins Shall Meet

The DigiDestined finally make it to the Rose Morning Star, where they sneak into Cherubimon's Castle and talk with the imprisoned Ophanimon, the one who chose the other DigiDestined, about the Digital World. They are interrupted by Cherubimon Operation: Free Ophanimon, who slowly defeats them and steals their Spirits. In an act of sacrifice, Ophanimon steals the Spirits back and upgrades Takuya's and Koji's D-Tectors for Unified Spirit Evolution, Takuya and Koji's Evolution Revolution with which they win the first round against Cherubimon. Cherubimon's initial defeat releases an ancient criminal IceDevimon, who seals Takuya and Koji. This requires the rest of them to fight. Koichi takes charge in this battle, leading to the defeat of the mass murderer, and is fully acclimated into the team. Ice Ice Baby

Cherubimon hasn't truly been defeated, however, and Koichi gives up his Spirits to allow Koji to unified spirit evolve once more. Their combined strength finally puts the dark angel down for good, but this does not fix everything that is wrong with the Digital World. Cherubimania The Legendary Warriors get another course in history from Baromon in the Tunnel of History only to be attacked by the Royal Knights Dynasmon and Crusadermon. The Legendary Warriors lose spectacularly, getting blasted to the Blue Moon. It Can't Be! Lucemon Reappears The first to awaken, Koichi discovers the reduced gravity and flags down a passing patrol to take them to the Moon Base. The DigiDestined are then forced to claw their way back to the Digital World proper by breaking through the Electromagnetic Stream. The Man In The Moon Is You

4-48 Koichi's Sacrifice

Koichi's sacrifice for the others.

The DigiDestined continue to lose battle against the Royal Knights, with each defeat meaning that a section of the Digital World has been scanned for the purpose of reviving Lucemon. All along the way, Koichi is haunted by the fact that even when the entire group is hurt to the point that their Fractal Code show, he remains more or less unscathed. At the battle at the Autumn Leaf Fair, Crusadermon reveals to Koichi the truth: he has no body in the Digital World and exists only as a spirit. Koichi takes this to mean that his body in the Human World is dead. All Aboard The Tag Team Express Koichi is deeply shaken by this revelation, only compounded by the fact that, at Ophanimon's Castle, Koji asks if they'll meet in the Human World. Bokomon reveals to Koichi that he overheard what Crusadermon said, but Koichi swears him to secrecy. The DigiDestined eventually lose the castle itself to the Royal Knights, which leads to Lucemon's successful revival and the destruction of the Digital World. To Make The World Go Away Disheartened by their utter failure, it takes seeing the Digi-Eggs and children they saved from the Village of Beginnings for the DigiDestined to find hope again; Koichi, in particular, bonds with a Poyomon. They manage to fully defeat the Royal Knights this time, only for Lucemon to sweep in and steal their fractal code to digivolve into his Chaos Mode, destroying the very moons they stand on. When Knights Fall...

4-50 Koichi's Revival

Koichi's miraculous revival.

In the remnants of the world, Koichi attempts to tell Koji the truth, but they are interrupted by Lucemon opening a bridge to the Human World. Forcing a battle with the fallen angel, Koichi as Loweemon is knocked away in the struggle. This allows him to escape Lucemon's Ultimate Sacrifice attack even when it decimates the others. Knowing that the others cannot take another attack, he takes the strike for himself. Bequeathing the Spirits of Darkness to Koji, Koichi's soul is scanned by Lucemon. His final act allows the others to become Susanoomon, which ultimately gives them the power to defeat Lucemon and save the Digital World. The Brothers Yin and Yang

On their way back, Loweemon, AncientSphinxmon reborn, reveals that Koichi is not yet deceased. The DigiDestined storm the operating room where Koichi is flat-lining. Through their tears and light, a miracle occurs. Koichi awakens, and the DigiDestined are completely united to celebrate their victory. In the aftermath of their journey, Koichi reunites Koji with their birth mother, happy that he no longer feels alone. Koichi makes the resolution to walk into the future with his friends at his side. End of the Line

4-50 Koichi Ending 1 4-50 Koichi Ending 2

On the day of their birthday after their journey, Koichi directs an internal monologue to his twin on his way to meeting him. He remembers how he used to feel lonely in crowds and realizes that it was because Koji wasn't there. He tells Koji about how much he wanted to meet him before, and that though he still feels guilt about that his actions as Duskmon, Koji's smile is like absolution to him. He tells Koji how safe he makes him feel, deciding that he would ultimately thank Koji for being born with him. From Kōichi to Kouji...

Other Appearances[]

Digimon BattleSpirit 2[]

Koichi Kimura is one of the fighters in this game, unlocked after the game has been beaten twice. His default form is Loweemon with the ability to slide evolve to JagerLoweemon, and he can evolve to AncientSphinxmon for a finishing move. His stage is the Terminal, which is based off of the Dark Terminal where Takuya finds himself after losing hope in the battle against Duskmon.

Digimon Rumble Arena 2[]

Duskmon Character Select ra2
"With blood-red eyes and glowing double swords, Duskmon's limitless command over dark forces can plainly be seen."

Duskmon is one of the obtainable boss Digimon in the game. He is unlocked by defeating him in the Chaos Wasteland.


Koichi has three theme songs: the vocal "Oreta Tsubasa de -With Broken Wings-", the instrumental "Yami no Theme" (闇のテーマ? lit. "Theme of Darkness"), and the English only "Darkness in My Heart". As Duskmon, he also has another theme song titled "Blader". A version of his Spirit Evolution and fractal code digitize speech appears on Digimon Frontier: Christmas Smile as "Spirit Evolution!! ~Kōichi-hen~". He speaks the "From Kōichi to Kōji..." track in the CD drama, Digimon Frontier Original Story: Things That Want To Be Told.

From a franchise standpoint, Koichi is a part of the Spirit Singers, a group composed of his fellow DigiDestined from Digimon Frontier. They debut in the Digimon Frontier: Christmas Smile album.

Digimon Forms[]

As Duskmon, Koichi has no memory of his past until he almost killed Koji during their first two confrontations. Hearing Koji's name being said over and over gave Duskmon great pain. After this, Duskmon fought Koji in order to learn the connection between them. Cherubimon gave him his Beast Spirit to become Velgemon but Ophanimon restored Koichi's memories, freeing him from his Spirits' control, but not from the influence of Cherubimon. It wasn't until Koji purified the defeated Duskmon that Koichi was free from Cherubimon's control.

After realizing that darkness does not equate to evil, Koichi transforms his Spirits into the Spirits of Darkness without evil, with which he channels AncientSphinxmon's true power.


H Spirit of Darkness b

H Spirit of Darkness

Duskmon is Koichi's initial Human Hybrid form, which he undertakes with the corrupted H Spirit of Darkness. Duskmon is coldly rational and overwhelming in his power, wielding his "Blut Evolution" (Deu: Blood Evolution) swords with enough power to match even Fusion Hybrid Digimon.

After traveling to the Digital World, Koichi is manipulated into becoming Duskmon, who serves as Cherubimon's loyal servant. Ne'er The Twins Shall Meet Duskmon is the strongest of Cherubimon's minions, able to take the full force of the DigiDestined's combined strength. Darkest Before Duskmon Duskmon's greatest weakness is Koichi's connection to Koji; through this, his subservience to Cherubimon is discarded in favor of an unrelenting search for the truth, which ultimately allows Duskmon to be defeated. My Brother In Spirit

Through Koichi's conviction, Duskmon is purified into Loweemon. Ne'er The Twins Shall Meet


  • Deadly Gaze[5] (Geist Abend, Deu: Ghost Evening): Emits shining energy from the eyes all over his body and the mouths on his arms, placing the opponent under hypnosis.
  • Lunar Plasma[6] (Eroberung, Deu: Conquest): Slashes a full moon-like arc with the Blut Evolution, absorbing the opponent's power and making it his own.
  • Memory Disturbance (Gedächtnisstörung): Shifts through the memories of his target.

Attacks in Digimon Rumble Arena 2

  • Brute Strike (Blut Strike, Deu: Blood Strike): Charges his foe with the "Blut Evolution" swords.
  • Death Gaze
  • Ghost Move: Teleports toward his foes.
  • Geist Blade Storm (Eroberung Storm, Deu: Conquest Storm): Slashes the area around him with the power of his "Lunar Plasma" technique.


Velgemon t
B Spirit of Darkness b

B Spirit of Darkness

Velgemon is Koichi's initial Beast Hybrid form, undertaken when he slide evolves using the B Spirit of Darkness. Velgemon sacrifices Duskmon's rational thought for flight and an even greater power.

In an attempt to cement his control over his Warrior, Cherubimon gives Duskmon the B Spirit of Darkness to become this ferocious beast. Added to the already powerful Duskmon, Velgemon is powerful enough to defeat even BeoWolfmon. O, Brother, Who Art Thou? It takes the combined power of both BeoWolfmon and Aldamon to defeat Velgemon for good, reverting him back to Koichi and free from Cherubimon's control. My Brother In Spirit

Through Koichi's conviction, Velgemon is purified into JagerLoweemon. Ne'er The Twins Shall Meet


  • Dark Obliteration (Zone Deleter): Flaps its wings with all its power, blowing away the opponent and all of the space around them to another dimension.
  • Dark Vortex (Master of Darkness): Changes the opponent's nature to darkness and manipulates them to its heart's content.


Loweemon t
L Spirit of Darkness b

L Spirit of Darkness

Loweemon is Koichi's second Human Hybrid form which he undertakes with the purified L Spirit of Darkness. Loweemon is powerful but flexible, wielding the "Danzai no Yari" (断罪の槍? lit. "Spear of Conviction") and "Shokuzai no Tate" (贖罪の盾? lit. "Shield of Atonement").

Koichi first becomes Loweemon when he purifies the Spirits of Darkness upon confronting Cherubimon. He uses this newfound power to defeat Cherubimon's shade with the true power of darkness. Ne'er The Twins Shall Meet Loweemon becomes Koichi's default battle form, only turning into JagerLoweemon when strictly necessary. He doesn't spend too long fighting as Loweemon, however, as he gives his Spirits to Koji for Unified Spirit Evolution to MagnaGarurumon, one of the only Digimon strong enough to face their new foes. Takuya and Koji's Evolution Revolution Koichi ultimately gives up his Spirits, including his ability to become Loweemon, when he sacrifices himself to protect against Lucemon's attack. The Brothers Yin and Yang

Koichi leaves the Spirits of Darkness much changed from their original state. When AncientSphinxmon reawakens, he does so in Loweemon's form. End of the Line

Loweemon is Koichi's default form in Digimon BattleSpirit 2, and the Terminal is his home stage. He has access to his Shadow Meteor and Shadow Lance techniques.


  • Shadow Meteor (Endlich Meteor, Deu: Final Meteor): Gathers energy in the jaws of the lion head on his chest and releases a burst of energy.
  • Shadow Lance (Ewig Schlaf, Deu: Eternal Sleep): Raises his spear, spinning it and gathering momentum and then dashes forward, thrusting his spear forward.


JagerLoweemon t
K Spirit of Darkness b

K Spirit of Darkness

JagerLoweemon[7] is Koichi's second Beast Hybrid form which he undertakes when he spirit evolves using the purified K Spirit of Darkness. JagerLoweemon offsets Loweemon's skill and weaponry for more power, though only as a last resort. Koichi never spirit evolves into this form directly.

Koichi first becomes JagerLoweemon when he purifies the Spirits of Darkness upon confronting Cherubimon. He uses this newfound power to defeat Cherubimon's shade with the true power of darkness. JagerLoweemon only appears when Koichi is in dire straits, often as a finishing blow Ne'er The Twins Shall Meet though he loses the ability to become JagerLoweemon when he gives his Spirits to Koji to become MagnaGarurumon. Takuya and Koji's Evolution Revolution Koichi ultimately gives up his Spirits, including his ability to become Loweemon, when he sacrifices himself to protect against Lucemon's attack. The Brothers Yin and Yang

JagerLoweemon is Koichi's beast form in Digimon BattleSpirit 2. Korikakumon has access to his Ebony Blast and Dark Master techniques.


  • Ebony Blast (Schwarz Donner,[8] Deu: Black Thunder): Releases a burst of dark energy as the pistons on his back recoil and can continue releasing bursts.
  • Dark Master (Schwarz König,[8] Deu: Black King): Leaps forward as the gems on his body glow and unleashes a giant burst of dark energy in the shape of a black lion, slicing straight through his enemies.


Rhihimon toy

Rhihimon is Koichi's Fusion Hybrid form.

In the virtual pet D-Tector, Koichi can digivolve to Rhihimon.[2] His Loweemon and KaiserLeomon toys can also digivolve to Rhihimon.




Mercurymon is Koichi's Human Hybrid form which he undertakes when he spirit evolves using the H Spirit of Steel.

In the virtual pet D-Tector, Koichi can digivolve to Mercurymon.[2]



Sakkakumon is Koichi's Beast Hybrid form which he undertakes when he spirit evolves using the B Spirit of Steel.

In the virtual pet D-Tector, Koichi can digivolve to Sakkakumon.[2]

Notes and references[]

  1. Digimon Encyclopedia: Voice Actors: Digimon Frontier Character Cast List
  2. 2.0 2.1 2.2 2.3 2.4 2.5 D-Tector
  3. Koichi never reaches Rhihimon in the anime. However, the Hybrid-Digivolving Figures: Loweemon and Hybrid-Digivolving Figures: KaiserLeomon toys are molded over Koichi bases, which, when combined with each other, form Rhihimon for a sort of Fusion Evolution. It is listed here for completion.
  4. Digimon BattleSpirit 2
  5. This attack is named "Geist Blade" in Digimon Rumble Arena 2.
  6. This attack is named "Gruesome Grab" in Digimon Rumble Arena 2.
  7. This form retains its Japanese name of "KaiserLeomon" on the Hybrid-Digivolving Figures: KaiserLeomon toy.
  8. 8.0 8.1 While the correct German translation for "black" in this situation would be "Schwarzer", the Japanese name for the attack pronounces it simply as "Schwarz".