The Sewn-lip Man

Hiro Amanokawa gets involved in a paranormal incident and receives a message from his missing father to take care of the mysterious Gammamon as a little brother.

Summary
In an era when holograms are an everyday technology, urban legends about Hologram Ghosts—ghost-like paranormal entities that resemble glitchy holograms—have spread in recent years.

At Kobayashimaru Confectionery, Mika Kashiwagi tells her friends Aoi Udagawa and Ruli Tsukiyono the Hologram Ghost known as "Sewn-lip Man" has been seen again. The Sewn-lip Man,, manipulates nearby clocks and asks victims the time. When they don't know, he steals their time, aging them into elders. At Hazakura Private Academy, a girl looking for her pencil case is attacked by Clockmon and turned into an old woman. Ruli tells her friends she'll look for the Sewn-lip Man and shows her "Lirurun" post asking for info on the entity.

The next day, at Hazakura Boys' Dormitory, Hiro Amanokawa wakes up and goes through his day. During breakfast he and his friend Kotaro Nomura discuss the rumors about the girl attacked by Clockmon. The dorm's leader, Kiyoshiro Higashimitarai, reminds them of the time. As Kiyoshiro's bandages are brought up, Kotaro asks if he was a victim of the Sewn-lip Man, and gets scolded for possibly jinxing him. When the boys see a police car on way to class, Hiro remembers how his father, Hokuto Amanokawa, disappeared six months prior: While preparing breakfast at home, Hiro called out to his father but found his office empty with a burned hole in the ground and damaged surroundings in a sphere's radium. The hole had a blue smartwatch, a Digivice -V-, with a memory card, a DIM Card, inserted in it. The police, after checking the event, classified Hokuto as missing.

After taking a teacher's request, Hiro and Kotaro come across the auditorium where the attack happened, marked by police tape holograms. Kotaro tells Hiro the news spread, making their school famous, and shows the Lirurun post to him. Deciding to try to take a picture of the Sewn-lip Man for Lirurun, Kotaro asks Hiro to help him break into the auditorium. As they enter the building without incident, Hiro starts to doubt the rumors, but the two are confronted by Clockmon. Kotaro happily takes pictures of Clockmon, who turns the boy into an old man. As he is about to attack Hiro, Aida-sensei and the Math Teacher enter to check on the break-in and escort the boy out. Kotaro is hospitalized.

At night, Kiyoshiro gives Hiro a talisman to protect him from the Sewn-lip Man. Hiro hears sounds from an invisible source in his room, and has a bunch of DIM Cards thrown at his head. Recognizing the objects, he tries each one into a Digivice -V- until his room mysteriously transforms with tall grass suddenly appearing everywhere. Hiro sees, who points at the boy's desk and leaves. The boy finds a strange creature that claims to know his name and calls itself. A hologram recording of Hokuto appears and explains to Hiro he is in the and Gammamon is a, a creature unknown to mankind. Hokuto tells Hiro to treat Gammamon as his little brother and take care of him and also instructs him to insert the DIM Card into the Digivice -V-. The recording ends and the room returns to normal. Hiro realizes he can see Gammamon when wearing the Digivice -V-, and manages to materialize him with the DIM Card.

Clockmon tries to attack Hiro again in his room, revealing he likes to look at stolen time from humans, but Gammamon fights to protect him, taking the battle all the way to a park. Clockmon tries to steal time from Gammamon, causing a to emanate from the small Digimon. Remembering how Clockmon's power works, Hiro throws a chestnut branch at the Digimon's light beam, aging it into a tree, which flies in Clockmon's direction. Remembering his father's request, Hiro's feelings synchronize with Gammamon's, allowing him to call his new brother's "Breaclaw" attack, damaging Clockmon, and returning all the stolen time to its owners, reverting them to their natural ages. An injured Clockmon runs away promising to steal Hiro's time at another opportunity. Hiro is left confused by these events.