Sex Sensou ~Ai Aru Ecchi wa Kinshi Desu!~

It seems like it could be found anywhere...an ordinary coeducational school.
However, for several decades now, this school has been the site of a battle between men and women.
"SEX War'' is a serious battle that stakes the existence of men and women. A world where the only option is to defeat the other through sex.
The main character enrolled in such a school with his childhood friend.
"I am... your enemy"
A declaration of war from a childhood friend! A female honeypot that attacks! Unavoidable! ? A collision is inevitable! ?
--The genital showdown is about to begin...

Translated from DLsite