Sendou Akira

Main character. A former professional tennis player.

Through the arrangement of his older sister Manami, he is called in as a temporary coach at St. Celine's Academy, a prestigious tennis school.

Although he is not at all keen on the job, he reluctantly accepts the offer because Manami is pressing him and he has nowhere to live and no money to spend.

However, he is quite anxious about it, as he has little experience teaching others and has not been on the court since he retired, much less working in a tennis-related job