Oicho is a supporting character in the anime Megalobox. She is introduced as one of Sachio's friends and part of the group of street children connected to the story's working-class environment. In the first season she remains mostly in the background, appearing alongside the other children with minimal lines. She is a girl with light olive hair and ochre eyes.

In the sequel season, Nomad: Megalobox 2, Oicho is given a more substantial role with significantly more dialogue and character development. Years have passed, and she has grown into an engineer who is apprenticing under Abuhachi and helps out at his shop. Her central motivation is to acquire a skilled trade and build a dependable adult life, and she approaches this goal with steady diligence. She is characterized as someone working hard to learn a craft and become a capable professional, described as developing into a woman who is cool rather than cute.

Within the story, Oicho functions as part of the younger generation who remain connected to the established characters, and her presence at the shop ties her to the everyday operations that support the central cast. Her most significant relationships are her friendship with Sachio and her apprenticeship under Abuhachi, who serves as her mentor in engineering. Through this apprenticeship she grows from a nearly silent background figure into a more prominent, hardworking young woman with practical mechanical skills.

Her notable ability is her technical aptitude for engineering and mechanical work, which she develops under Abuhachi's guidance. Her role is similarly minor in the manga adaptation Megalobox: Shukumei no Souken. Overall, Oicho's arc reflects steady growth, from a child on the margins of the story to a young adult with a trade, a mentor, and a place in the community.