Age: 16
Height: 160 cm
Weight: 52 kg
Likes: Jojo's Bizarre Adventure
Masuzu is Eita's classmate and his girlfriend. A first year high school student, who spent nine years overseas. She is considered to be the school beauty and is constantly confessed to by male students before she forms a fake relationship. She is bold and acts more evil out of school and she is very devious. Like Chiwa, she is a terrible cook.
Like Eita, she actually hates romance and only blackmails him to be her boyfriend to stop getting confessions from people.
In novel 4, Masuzu reveals that she hated Eita from the beginning, as he was the only one who wasn't charmed by her face or look like he was paralyzed just by looking at her. Her real personality is sadistic: she loves seeing people's depressed faces, but doesn't want to show this to people because they would hate her.
She has a complicated relationship with her father who lives in Sweden, and refused to go back there because of Masuzu searching for her mother, who was outcasted by him.
In the end of the anime, Eita chooses her over the other girls.