Our protagonist gets caught in flagrante with his neighbour by his childhood friend Rin. This finally forces her to shed her tsundere skin and come forward: she’s been saving her virginity for him and she won’t let some random neighbourhood lady get a head start on her!

So she (rather forcefully) joins in on the party...
*All characters depicted in this work of fiction are adults, regardless of their visual representation or textual description, and are not based on any real person*