If it’s sex that you want, then why not me?
Self-centered Yuichi has gone through so many women that there is no one left willing to date him at the university. The only thing Yuichi really misses and likes about women, though, is the sex, so studious and cool Kanae, Yuichi’s best friend and complete opposite, takes advantage of his horniness and offers to be his sex partner. I wouldn’t say that Kanae has ulterior motives, but there is a reason other than pleasing his friend that he offers such a thing: Kanae has been secretly in love with Yuichi since the day they met. Unsurprisingly to readers, Yuichi takes him up on the offer, the start of weeks of nearly non-stop sex.
Yuichi doesn’t stop with just calling it casual sex; he declares them lovers, essentially locking them into a relationship. Kanae is half thrilled and half scared; thrilled that he can call Yuichi his own, even if it’s just until he moves onto his next woman, and scared of the moment when Yuichi really does move onto that next woman. Even though this seesaw of happiness and fear is agonizing, he never reveals his true feelings, afraid that Yuichi will move on that much faster.
If Kanae sounds too angsty or mousy, then have no worries; that’s not really what Body Language is all about. That nearly non-stop sex I mentioned earlier–I wasn’t exaggerating. They go at it, in the narration’s own words, “like bunnies”. Yuichi’s desire never seems to be satisfied, wanting just moments after they finish to give it another go. He doesn’t even let poor Kanae rest while at school or during one of their commutes (yes, a commute). They do get emotionally closer at the same time, accompanied by an abundance of fluids, fondling, and moaning, and ultimately leading to a heart-stopping outburst of feelings; quantitatively speaking, however, sex wins out.