Minatsu Nakazato is a student at Asaoka High School and the pitching ace for the softball club. Her father is a lesser-known professional wrestler. She faces unwanted romantic advances from several individuals, including classmate Shū Akiba and her teacher, Kango Yamazakura, who advises both the softball and boxing clubs.

To escape these persistent pursuers and avoid local gangsters, Minatsu creates an alter ego named Maria Sudō. Living in the same apartment building as Naoto Kadomatsu, a third-year boxing champion from another school, she maintains her disguise as Maria. Kadomatsu develops romantic feelings for Maria without knowing she is Minatsu.

Minatsu possesses a curt and somewhat rough personality. Her dual identity complicates relationships, particularly fueling a rivalry between Akiba and Kadomatsu after both discover the truth and vie for her affection. Akiba joins the boxing club specifically to compete against Kadomatsu, aiming to win Minatsu's approval through athletic success.

Her background involves balancing her true self with the fabricated Maria Sudō persona, a strategy that complicates her life but offers temporary respite. This double life unravels when Kadomatsu learns Minatsu is Maria, intensifying the romantic rivalry.

The resolution of her story differs between media: the manga leaves her ultimate romantic choice ambiguous, while the OVA shows her developing feelings for Yamazakura and marrying him. Yamazakura's orphaned niece, Chika Tanaka, strongly approves of and actively supports their union in the anime conclusion.