Yuuta Asuka
About
Yuuta Asuka is the manager of the boy's soft tennis club and the younger sibling of Izumi and Hikari Asuka.
Kind but lacking in self-confidence, Yuuta is sometimes taken advantage of by others. The members of the soft tennis club view their manager as a caring and reliable person, defending Yuuta when required.
Their preferred name is Yuu, and though they are still not sure of their gender, they have said that non-binary is the label that fits them best. This was revealed in episode 8, where Yuu opens up to Maki. However, at this point in the series, Maki and Yuu's sisters are the only characters who call them by their preferred name and pronouns.
(Source: Wiki, edited)