Enomoto acts as Kana Iriya's primary guardian and handler. Introduced as her supposed older brother, his exact familial tie remains undefined. He answers to military authority linked to the nearby air force base where Kana lives, working to conceal her role in a secret extraterrestrial conflict.

His duties focus on overseeing Kana's well-being and ensuring her readiness to pilot the advanced "Black Manta" fighter. Typically relaxed during routine interactions, he displays fierce protectiveness and a capacity for violence when Kana's safety is threatened or protocols are broken. This manifests when he drags her from the school pool after her first meeting with Naoyuki Asaba and intervenes aggressively if she misses scheduled check-ins.

Enomoto coordinates with colleague Mayumi Shiina (posing as the school nurse) to monitor Kana at school. He arranges limited social opportunities for her, like requesting Naoyuki be her partner for the school festival folk dance. His frustration surfaces visibly as Kana's physical state deteriorates, especially after a food-eating contest triggers severe health issues. His interventions grow more urgent with her increasing piloting strain – frequent nosebleeds, seizures, and degrading senses.

When Kana and Naoyuki attempt to flee, Enomoto tracks them down. After recovering Kana, he reveals the full context of the secret war to Naoyuki over a meal, disclosing humanity's reliance on Kana as the final defense and confirming the climactic battle's imminent timing. He orchestrates Naoyuki's transport to the military base to persuade a reluctant Kana to fight, prioritizing the mission despite its lethal cost to her.