Choosing which high school club to join can be a daunting task. After all, there are only so many hours in the day, not to mention the power struggle between cyborgs and part canine-females. At least, thats the conundrum that Haruki Komaba finds himself trapped in.

Airi Kuze is a mechanical science master with a crush on Haruki. Ayana Hizuki is a half-dog, half-girl chemical science master whos also fond of Haruki. Unfortunately for Haruki, he accidentally promised to join both clubs and finds himself in the middle of a fierce battle for his membership and, if Airi has anything to say about it, his hand in marriage.

As if things werent complicated enough, Ayanas perverted older sister Touko has decided to intervene on her younger siblings behalf, bringing her own brand of sexually charged chemical science into the mix. Harukis going to have a difficult time deciding on a club. If the girls dont end up tearing each other apart first, that is.