Ikeuchi is a young man with short red-brown hair in a bowl cut and square-rimmed glasses. His monster form transforms his head into a functional surveillance camera, enabling visual observation, recording, and data distribution to external storage or the internet within a limited range. This ability facilitates his voyeuristic tendencies, specifically targeting Chihiro Yoshioka. Characterized by consuming cowardice and self-preservation instincts, he prioritizes his own safety and Chihiro’s well-being above all, readily betraying others to achieve these goals. He exhibits an obsessive fixation on Chihiro, stalking her extensively using his camera abilities yet lacking the courage to confess. This obsession fuels intense jealousy during her interactions with Shuichi Kagaya, resulting in accusatory behavior and attempts to sabotage their connection. He distrusts others, frequently blaming them for unfavorable situations, and demonstrates manipulative tendencies when threatened. His involvement begins when Clair Aoki discovers his contact information and group affiliation from the deceased Sudo. Fearing Clair and Shuichi under the mistaken belief they killed Sudo, he introduces them to Sayaka Koyanagi's group. His jealousy escalates upon witnessing Chihiro undress to enter Shuichi's monster form. He later shares this recording with Clair, intensifying her confrontation with Shuichi and Chihiro. Suspicious of Shuichi's explanations about Sudo's death, he stalks Shuichi at school, photographing interactions with Nana Mifune. When confronted, he demands Shuichi reveal hidden powers. During the group's investigation of a suspected alien crash site, they encounter Madoka's powerful faction. Surrounded and outmatched after injuries, Madoka offers protection and wish fulfillment in exchange for service and sacrificing one member. Ikeuchi panics, advocating surrender and suggesting sacrifice to save himself and Chihiro. He attempts to walk away during the group's debate, earning condemnation. Later, discovering Clair’s plan to use Isao's plant manipulation to grow toxic oleanders against Madoka's group, he betrays Koyanagi's pact. He flees to Madoka, begging for himself and Chihiro to join his clan, triggering lethal consequences. Narrative outcomes diverge: - **Anime:** Koyanagi executes him immediately during his betrayal attempt using her hair-wire choker ability. - **Manga:** He survives Koyanagi's initial attack. Later, he discovers the dying Madoka, who gives him 100 coins. During the final battle between Honoka and Shuichi, he attacks their merged form, refusing to accept a world "saved" by Shuichi. He uses the 100 coins to merge with Honoka, gaining darkness-based powers. He loses the ensuing battle and dies. His fixation on Chihiro drives his actions, culminating in divergent fatal conclusions across adaptations.