Koushiro "Izzy" Izumi

Koushiro "Izzy" Izumi (泉 光子郎) is a character in the and  series Digimon Adventure, Digimon Adventure 02 and Digimon Adventure tri.. He is a DigiDestined, partnered with, and the bearer of the Crest of Knowledge.

Appearance
In 1995, Izzy is a small boy with light skin, short, spiky red hair, thick eyebrows and dark eyes. He wears orange pajamas, and brown adult-sized slippers.

In 1999, Izzy is older, but very short for his age. He wears an orange button-up shirt with rolled-back sleeves, olive green shorts, light yellow gloves, light green socks, and purple and gray shoes with a yellow lightning motif. His underwear are light orange boxers with a white band.

After taking a bath in Devimon's illusory mansion, he wears a blue bath robe over his underwear, which is later revealed to be an illusion.

On March 4, 2000, Izzy wears a dark blue shirt under an open orange button-up shirt, light brown shorts, blue socks, and dark blue shoes.

In May 2000, when Gennai summons him back to the, Izzy wears an orange T-shirt with a white lightbulb line drawing on a grey square, dark green pants, dark red sneakers with black soles and laces and light yellow wristbands.

In April 2002, Izzy is 13 and finally taller, though still somewhat shorter than most teenage boys his age, and has cut his hair short. He usually wears the Odaiba Middle School uniform; a white buttoned shirt with long sleeves under a closed green blazer jacket, a dark blue tie, gray pants, white socks, and purple and grey shoes.

During summer, he wears a short-sleeved orange shirt with horizontal lines under an open green short-sleeved collared shirt. He also wears brown shorts and purple shoes with bright purple soles and a bright purple stripe motif. He is also seen wearing Odaiba Middle School's summer uniform: a white short-sleeved buttoned shirt with the Odaiba Middle School symbol on the left breast, light green pants, and a light blue tie.

During winter, he wears a dark red shirt with horizontal stripes, black raglan sleeves and a black collar. He also wears light brown pants and purple shoes with bright purple soles. Outside, he wears a green hoodie with white lining inside the hood and a large front pocket. While in Hong Kong, he wears his hoodie tied around his waist.

On March 25, 2003, Izzy wears an orange shirt with a thin green rectangle on the chest, green raglan sleeves and an orange collar, as well as light brown pants and brown shoes.

In April 2005, Izzy is 16 years old and retains his hairstyle in Digimon Adventure 02 and wears a neat version of the Odaiba High School uniform. In the chaotic battle against three Kuwagamon at the Haneda airport, he wears a formal outfit; a brown long formal vest with a white long sleeved shirt with a black bow tie on his neck, charcoal gray formal pants and black shoes.

During the battle against Alphamon, Izzy wears a simple outfit; a blue long sleeve sweater jacket with off-white outlines fastened with buttons, underneath is a white long sleeved button shirt, royal blue formal capris and green short boots and white socks.

In 2027, Izzy is an adult, though he remains the shortest of the male DigiDestined. His hair is now straightened and he has longer bangs which are combed to the left. He wears an olive green button-up shirt with rolled-back sleeves and dark green pants. At work, he wears a light blue coat with a mandarin collar and grey pants.

Description
Izzy is a computer expert and spends a large fraction of his time trying to figure stuff out on his "PiBook" laptop. He is very intelligent and knowledgeable, and often gets lost in thought while trying to figure out something new. He is extremely curious about the nature of the Digital World, and works ceaselessly to learn whatever there is to know about it. He is resourceful and dutiful, and quick to help his friends. He is somewhat socially awkward, even as a teenager when he is more confident in his ability. In the Japanese version, he is extremely polite.

Izzy lives with his adopted parents. He found out of his adoption by accident, causing him to distance himself from them, but eventually he accepted them as his true parents after they revealed the story of his adoption to him and told him about his birth parents.

Izzy is initially a member of the soccer club with Taichi "Tai" Kamiya and Sora Takenouchi, though he isn't particularly good at the sport. He later becomes the president of the computers club.

In the English dub, Izzy often says "Prodigious!"

In Digimon Adventure tri., Izzy became more focused on the infected Digimon they were currently facing which resulted in him getting stressed and fatigued. He is also a gadgeteer, through which he is able to invent Tai's new goggles and the virtual connection where all of their Digimon are able to enter by any computers, gadgets and machines. Izzy was revealed to speak French fluently during his parents' wedding anniversary when talking to Sora on his cellphone, at which she became completely annoyed at what he had said to her during their conversation.

Etymologies
Name used in the Japanese version of Digimon Adventure, Digimon Adventure 02, and related materials. First name written as Kōshirō in his room. Full name romanized as Koshiro Izumi in Digimon Adventure tri. and Digimon Adventure: Official Encyclopedia II.
 * Kōshirō Izumi (泉 光子郎)
 * Ja: Izumi (泉). Japanese surname that means "fountain", possibly a reference to "fountain of knowledge".
 * Ja: Kōshirō (光子郎). Masculine Japanese name that means "photon son". Likely a reference to, who uses electrical attacks.

Name used in the English dub of Digimon Adventure.
 * Koushiro "Izzy" Izumi
 * Koushiro. Alternate romanization of "光子郎".
 * Izzy. Similar to "Izumi".

Digimon Adventure
Izzy's real father was a genius mathematician. He and his wife died in a car crash when he was a baby. He was then adopted by Masami Izumi, a distant relative of Izzy's father, and his wife Kae. One night, when Izzy couldn't sleep, he overheard his parents talking about him being adopted. After this shocking discovery, he began to subconsciously distant himself from his parents and focusing on his computer.

In 1995, Izzy's family lived in Highton View Terrace. One night, he witnessed the battle between Red Greymon and. This event caused him to be chosen to be a new. The destruction created by the battle caused it to be labeled a terrorist attack, and the Izumi's moved away from the area.

Izzy brought his entire computer setup to summer camp, and is annoyed when none of it works due to the sudden snowstorm. To his chagrin, his technology won't work in the Digital World either. Once in the Digital World, Izzy is very curious about the nature of the Digital World and the Digimon, and tries to come up with theories to explain it all.

When the DigiDestined enter a factory, Izzy finds a large battery and enters. He wipes away a part of the hieroglyphics on the inner wall, causing the factory to stop production. He becomes the first to realize that everything, even the program, is living in the Digital World. He is also delighted to find out his computer works in this factory, and gets distracted trying to make sense of things. He even finds a code that activates his Digivice, though it burns out. Izzy’s skills with the computer soon prove to be extraordinarily useful for the group when, during the battle against, Tentomon suggests that Izzy reenter the code that activated his Digivice. When Izzy types it in, Tentomon digivolves into and destroys the Black Gear affecting Andromon.

When separates the DigiDestined, Izzy and Tentomon end up in the Ancient Dino Region. They find a temple, and Izzy recognizes the symbols on the ruins as being identical to those in the factory battery. He begins studying them, and is so preoccupied with his computer and his research that he barely notices when Mimi and arrive. Mimi is insulted by his indifference and runs away crying, with Tentomon in hot pursuit. When they both run into a maze, Izzy pulls out the map and locates Mimi’s, directing them out of the maze and saving them when attacks.

After he receives a message from, Izzy uses it to deduce that the Digital World is an alternate world that runs parallel to the Real World. He theorizes that the children may have left their bodies behind when they arrived in the Digital World (a theory that turns out to be false), but later warns Sora that dying in the Digital World would still be very real. After Datamon captures Sora, he figures that Datamon is still inside the pyramid, and helps Tai rescue her.

After Tai and disappear following the battle against, Izzy and Tentomon break from the other DigiDestined in hopes of finding Gennai and getting some answers. They runs into Vademon, who tricks Izzy into giving up his curiosity and regresses him to an accepting mind that does not question anything. During this state, he sends a message to Tai, telling him not to return to the Digital World. Tentomon frantically tries to get Izzy back to no avail; he slowly reverse digivolves back into and  before Izzy snaps out of it. Izzy gets his tag and crest and his curiosity back. In the ensuring battle, the Crest of Knowledge activates, and Digivolves into  and defeats Vademon. Following Izzy's fight with Vademon, Gennai loads his computer with the Digimon Analyzer. This program becomes invaluable when Izzy has to figure out the puzzle to 's special gate to the Real World.

Once the DigiDestined are back in the Real World, Gennai loads a couple of useful (and some not so useful) programs into Izzy’s laptop. One program tracks the movement of Digimon; Izzy sees Raremon attacking Tokyo Bay and rushes out there with Tentomon to stop him. Another program puts up a digital barrier, which stops the from taking Izzy and his parents away. Gennai also tells Izzy that the source of Myotismon’s power is in the Fuji TV station and describes a prophecy to him. The prophecy aids them in defeating ; when Izzy reads the prophecy out loud, the group follows its lines. and hit Matt and Tai with arrows of hope and light, which leads to  and  warp digivolving into their Mega forms, which is of tremendous aid in the battle.

In the lull between battles, Izzy’s parents reveal to him that he was adopted, and tell him of his birth parents. Izzy apologize to them for being so distant, and they tell him they're happy to have him as their son.

Izzy’s Digimon Analyzer becomes a more valued asset as the DigiDestined battle the Dark Masters. With a loaded a database of Digimon profiles, Izzy can name and describes the characteristics of new Digimon they encounter. However, is proves to be a hindrance against, as Izzy's usage of the computer allows him to track their movements around his city.

After Apocalymon is defeated, Izzy calculates that, because one day in the Digital World equals just one minute in the Real World, the DigiDestined could stay in the Digital World for 118 years. However, Gennai tells them that the time distortion was fixed with the defeat of, and that the solar eclipse would seal the barrier for an indefinite amount of time. Izzy says goodbye to Tentomon, thanking him for being a good friend.

Digimon Adventure: Our Game Wars!
On March 4, 2000, Izzy discovers a Digi-egg infected with a computer virus on the internet, and rushes off to alert the others. He comes over to Tai's house to watch the battle unfold. He is deluged with the number of e-mails coming in, and frantically begs their audience to stop sending them, as their lag is slowing and  down. After WarGreymon and MetalGarurumon DNA Digivolve into and take out all of 's clones, however, the remaining Diaboromon is too quick for Omnimon, always jumping away just as Omnimon spots it. Izzy comes up with a plan, forwarding all of the support emails to Diaboromon to slow him down. Omnimon manages to destroy Diaboromon just seconds before the nuclear missiles it launched would have detonated in Japan.

Digimon Adventure 02
On May 2000, Izzy arrives in the Digital World and gives up his Crest power to free the Digimon Sovereigns. As a result, Tentomon loses the power to become.

Sometime before April 2001, Izzy leaves the soccer club and joins the computers club instead. He quickly becomes a respected member, and is appointed president of the club. He becomes acquainted with Yolei Inoue, another member of the computer club, who looks up to him.

During all this time, Izzy keeps in touch with Gennai, sending him emails frequently.

As the new DigiDestined gather to battle the Digimon Emperor, Izzy mentors them and continues to play his technical role. He monitors the Digital World and alerts the new DigiDestined to upcoming troubles and problems. Izzy researches the new Digivices and figures they have three new functions, dubbing them the D-3s.

In summer, Izzy is kidnapped into another dimension and regresses in age thanks to Wendigomon. The new DigiDestined reverse this.

After school is out for the summer, Izzy theorizes that the power of the D-3 is what really opens the gate to the Digital World. This theory proves to be correct, and gives the DigiDestined the ability to open up ports at any time and any location, rather than being limited to simply using the school’s computer lab to move in and out of the Digital World. After Izzy and Cody find the Digimon Emperor's base, the new DigiDestined decide to go to the Digital World and stay there until they defeat the Digimon Emperor. Matt and T.K. convince their father to chaperon a camping trip for Izzy, Matt and Tai as a cover up for the younger kids. Izzy later devises the plan to invade the Emperor’s base; with Cody’s information that a pipeline will cross paths with Ken’s base, he directs and  to create a diversion.

Sometime later, while Izzy monitors the Emperor's downed base, he discovers that it is about to explode. He alerts the new DigiDestined and keeps them updated on its condition while they're trying to stabilize it. Following and 's Digivolution into, Izzy invites the new DigiDestined to his house, and explains how DNA Digivolution works and why the older DigiDestined's Digimon can't Digivolve past Champion anymore.

Izzy later takes care of while Yolei is on a class trip to Kyoto. He visits Ken in his house to discuss Ken's past experiences with the Digital World and the Dark Ocean, and explains to him why the new DigiDestined's Digivices changed their shape and functions. After realizing that Poromon is tired from being in the Real World without his partner for so long, he hands Poromon over to Ken so he can take him to the Digital World to recharge.

On Christmas Day, as Control Spires and wild Digimon appear in the Real World, Izzy gathers all the Japanese DigiDestined in his room and explains the situation. He uses his computer setup to allow Gennai to materialize in the Real World. This allows Gennai to deliver the Harmonious One 's power to the DigiDestined, so that their Digimon can once again reach their highest forms. Izzy, Kari and their Digimon are sent to Hong Kong to help the Asian DigiDestined round up all the loose Digimon and send them back to the Digital World.

Izzy later aids the others in fighting the Daemon Corps and tracking down the children seeded with Dark Spores by Yukio Oikawa. He is present at Highton View Terrace when Oikawa gathers the Dark Spore children and is confronted by the DigiDestined. However, he remains behind when Oikawa, the children and the new DigiDestined enter the world of dreams. When the world is engulfed by MaloMyotismon's darkness, he goes with older DigiDestined and their families to the site of the summer camp from which they were transported to the Digital World years ago. He and the older DigiDestined manage to reach the Digital World from there, and help defeat MaloMyotismon once and for all with the light of their Digivices.

Digimon Adventure 02: Revenge of Diaboromon
On March 2003, Izzy is responsible for the planning and execution of the attacks on Diaboromon. He is the one who gathers all the DigiDestined to help defeat Diaboromon and stop the havoc it wreaked on the Internet and the Real World. He is able to decipher Diaboromon's plan to send Kuramon into the Real World and sends the DigiDestined to go capture them.

After Digimon Fusion


By the year 2027, Izzy sets up a research team with Jim Kido and Haruhiko Takenouchi to study more of the Digital World than what the human population already knows. He has a daughter, with a Motimon.

PSP game
When Machinedramon is revived by Apocalymon, Izzy refuses to give up and tells Tai that he and Tentomon will fight, and causes Tentomon to warp digivolve to.

Digimon World Re:Digitize: Decode
Taiga can fight Izzy in the.

Digimon Masters
Izzy appears in Digimon Masters as part of the June 2019 Odaiba update, which follows the events from Digimon Adventure in which tries to find the Eight Digidestined.

As of July 3, 2019, Izzy is usable as a playable character.

Music
Izzy has three Japanese image songs; "Version Up" and "Open Mind", sung by Umi Tenjin. He has an additional image song, a duet sung by Tenjin with Takahiro Sakurai as, called "Sekaijuu no Keshiki wo!" ("The Scenery of the World!"). Tenjin also participates in participates in "Bokura no Digital World" ("Our Digital World"), and in the male Digimon Adventure characters' rendition of "Butter-Fly" in the Digimon Music 100 Title Memorial Box.

Notes and references
Izzy Izumi 泉光子郎 Izumi Koushiro