|Nanatarou V. Yamada|
Nanatarou V. Yamada is Mizuki's roommate, first appearing in chapter 20 and being properly introduced in chapter 21. He instantly falls for Mizuki and declares he wants to marry her, much to Takeru and Mizuki's dismay.
Yamada is a tall and lithe young man with wavy, tan hair that reaches his lower back. His bangs are parted slightly, with two long locks flowing past his shoulders. He is drawn to look extremely beautiful, most girls at Taiju High fell in love with him when they first saw him.
While attending Taiju High, he wears the standard boy's uniform, with lingerie underneath. Yamada is fond of wearing lingerie, and oftentimes rips off his clothes to reveal them in moments of intensity.
Yamada is flamboyant, passionate, shameless, and stubborn. Despite being told numerous times by Mizuki's friends that Mizuki was male, he persisted in referring to Mizuki as a girl, and saying he wanted to marry her.
Yamada is dedicated to anything he sets his mind to, and goes to comedically great lengths to get what he wants. When he decided he wanted to marry Mizuki, he continued to hit on her, even after being beaten by Takeru. When he pretends to date Mizuki to avoid Tamako, he is initially distraught when Mizuki claims to be male and makes Yamada seem homosexual. Yamada quickly reinforces this by declaring that he is in love with a man, despite him not being so.
Yamada cares deeply for Mizuki, going as far as to say he would date Mizuki whether they were a boy or a girl. When Mizuki is moved to the girl's dorm, he is heartbroken, and attempts a rescue mission with the help of Ide (which fails).
Yamada's family owns the Rainbow Flower company, which manufactures women's lingerie. As a child, Yamada dealt with abuse from his classmates because of this, and asked his father what he should do. Yamada's dad encouraged his son to disregard what others said and be proud of who he is. He then embraced the family business and would begin wearing lingerie, like his father.
When Yamada met Daikawa Tamako, she instantly fell in love with him. Yamada was excited to share his passions, but quickly found that she wasn't interested in his lifestyle. Yamada describes her as destroying everything he lives for, and so he evades her. When he realized that he wouldn't find the validation he was looking for from Tamako, he decided to stop hiding who he was. This is what inspired Yamada to shamelessly wear lingerie in public, sometimes wearing nothing else.
- Yamada knows morse code, to a degree. In chapter 42 he attempts to signal Mizuki for help by blinking in morse code, to no avail.
- Yamada is pansexual, he declares in chapter 45 that whether Mizuki is a boy or a girl isn't important, he still loves them as a person.
- It's a running gag of Yamada being interested in spotted garden eels. He references a song about them in chapter 26, and while on a pretend date with Mizuki in chapter 44 he can be seen admiring a painting of two eels.