|“||Yamai-san is a straight-up yandere.||”|
|Full Name||Yamai Ren|
|School||Itan Private High School|
|Manga Debut||Chapter 5|
Ren Yamai (
Ren sports a long auburn hair with flyaways at the end and bangs adorned with a red ribbon over her left ear. Yamai wears the Itan Private High School uniform on school days and dresses in more girly fashion on off days.
Ren is a the leader of the ladies' group in Class-1 and, like the whole student body, a member of Shouko's entourage. She calls Shouko "Komi-sama" and secretly worships her to a greater degree even than the rest of Itan High. Ren shows a violent and conniving true side of herself when someone she sees as unimportant grows close with Shouko, namely Hitohito. Despite her initial scheme against Hitohito and Shouko's rejection of her advances as a result, Ren learned to tolerate Hitohito and managed to tone down her insanity enough to become one of Shouko's companions. Still, throughout the story, she has attempted various tactics to catch a glimpse of Komi's underwear or take a panty shot, touch her boobs or otherwise feel her up, be touched by her, etc.
As a second year at Itan High, Ren is shown to have made friends with Manbagi Rumiko's friends, the gyarus, in her class.
- Her name "やまい れん (Yamai Ren)" is written as mountain and well but can also mean illness which the word yandere came from. While "れん (Ren)" is an alternate reading of "恋 (koi)" which means love.
- She claims that she doesn't get along with Nakanaka Omoharu (and vice versa) but the two have a notable rivalry for Shouko's attention that causes them to repeatedly be seen acting in sync. (Their classmate Sukida Lily ships "Naka x Yama," often appearing when they bicker.)
- Ren shamelessly stalks Komi, waiting outside her house for days on end sometimes. She has a tendency to show up uninvited to events Komi had arranged with her other friends.
- Her idea for the Cultural Festival was the Haunted House, her ulterior motive being getting away with touching Shouko's butt under the cover of a dark classroom.
- Ren is a rather materialistic person; she spends her breaks on luxurious vacations and likes designer clothes and accessories. This suggests that (like the archetypal popular girl) she comes from a wealthy background.