Hakomine Academy is a prestigious high school known for its baseball team, which has won the national championships for many years now. First-year student, Inami Saki, sees one of their games and becomes interested in it, and succeeds in becoming the manager for the team.

Saki, excited about her new position, gets to know about the team's "tradition" from the chief manager of the team, Kurimiya Nozomi.
"It is the manager's job to take care of everything so the players can be in perfect condition--"

What Saki had not awaited was the tradition, where she would have to offer herself, no matter when, to the club members and pleasure and have sex with them - in other words, she was to become the team's "sex manager".

Saki eventually dedicates herself completely to the team, heart and body, while changing completely due to the twisted tradition...