There's a strange rumor going around the school that the socially awkward protagonist, Yaoyorozu Kurou, attends.
It says that "a boy and girl who kiss during class will be able to obtain happiness."

Everyone laughed off such a rumor and didn't take it seriously,
but then one couple went ahead and gave each other a deep kiss right in front of their friends!!
Then, their wish came true, and after hearing about it, other students started to do the same.

Amidst all this, another rumor started going around that said
"a boy and girl who secretly give each other oral sex in the classroom will receive even more luck"......!?

[Translated from dlsite]