I Forgot But The Body Remembers

From Naono Holics:

Yosshi (Yoshii Takara) is a wealthy investor who cashed in on the IT boom, and K.T. (Hanatani Keita) has been the CEO of an IT startup operating since he was in elementary school. Both of them are wily and dangerous people, but they're dating - except that K.T. was supposed to be stringing along Yosshi, who's 20 years older than him.

That's why it comes as a surprise to K.T. just how genuinely shocked and upset he is when Yosshi has an accident and loses his memory. He tries to help him regain it, and somehow, the best way to do that turns out to be sex...

But how effective is this method, really, and could there be things the two sly foxes aren't telling each other...?