Hiromi Oka, a first-year student at West High School, joins the tennis club admiring Reika Ryuzaki, aka Mrs. Butterfly, and senior Todo; she is a complete beginner, but as soon as she joins the club, the devilish coach, Munekata, sees her talent.

Hiromi Oka's been chosen to play on the top class Nishi High tennis team; the older girls glare coldly, even the kind and beautiful Madam Butterfly won't talk to her; Hiromi wants to quit the team, but Coach Munakata won't let her.

Regional preliminaries begin, and Hiromi is filled with dread; there to cheer her up is the kind Takayuki Todo; Madam Butterfly gives her favorite racket to Hiromi.

In the middle of her match, Hiromi gets a leg cramp and falls to the ground; Kyoko Otowa, full of contempt for Hiromi, demands the coach let her play a practice match.

Hiromi is devastated by the loss of her racket; but Coach Munakata couldn't care less, as his brutal training continues.

At last, the semifinals have begun; Kita High takes the first set, 6-2; Munakata's scolding makes Hiromi move.