3-nen C-gumi wa Furin Shitemasu

Synopsis

Set in a high school senior class where students can now marry without parental consent due to the implementation of the new “18-year-old adulthood” law, this unprecedented school suspense drama explores first love, pregnancy, marriage, and even infidelity. Not only are the students of Class 3-C involved in affairs, but so are their parents and teachers…!?
 
The protagonist of this work is Uemura Aoi, who transfers into Class 3-C at an elite high school after her parents get divorced due to her father’s affair. The story depicts how she reunites with Tachibana Iori, a male student who was her first love and is now married to another classmate, and how they fall into an illicit affair. Their romance eventually spirals into a scandal that engulfs the school and their parents, leading to a gruesome tragedy.

(Source)