Hanae Chin is a friend of Yuunosuke Sakurai, a Hodokubo High School baseball player. She observes his persistent lack of self-confidence and tendency toward indecision, frequently stepping in to offer direct motivation and clear direction. Her goal-oriented approach presents a stark contrast to Yuunosuke's timid nature.

Moved by the passion and dedication of the baseball club members during their training and games, she commits to supporting the club to achieve personal growth. After an invitation from Minami Kawashima, she formally joins the management team. Her extensive social network, ease in interacting with others, and refusal to be intimidated make her well-suited for gathering intelligence on opposing teams, a role she is later assigned.

Throughout the series, she maintains a particular focus on Yuunosuke's development within the team, providing external motivation and support whenever he reverts to uncertainty. This character appears exclusively in the anime adaptation.