Age: 15
Height: 164 cm
Weight: 43 kg
Sitting Height: 87 cm
Birthdate: May 21 (Gemini)

Yamada is a high school girl who is best described as oversexed, flirtatious and lustful. She is particularly vain and is unabashed in flaunting her looks in public. Upon entering high school her goal was to have intimate relations with 100 different men, but her insecurities as a virgin caused her to turn down any advances. Yamada believes the first step towards achieving her goal is to lose her virginity to an inexperienced boy leading her to pursue one Takashi Kosuda. While initially seeing him as a tool for her lust, over time she starts to develop genuine feelings for him. Despite living at home with her younger sister, Yamada is unashamed in her licentious habits which involve highlighting sexual terms in the dictionary and collecting erotic magazines which she keeps in her room.

Aiding her towards her goals is a personal deity who takes on the appearance of a super deformed version of Yamada, save the mustache, and floats around on a pink cloud. This character also acts as a narrator at times recapping past events as well as occasionally breaking the fourth wall to address the audience.