From the time when we're born, there are voices in our heads that suggest choices that can either make us fall into vice or abide by virtue. In the case of high school student Kodama, in the prime of his youth, his "Conscience" struggles to keep up with his "Temptation" as Kodama's perverted mind is filled with thoughts of his cute classmate, Hasumi. What's worse is that Hasumi asked Kodama to hang out!
It's basically at date at this point, right? (At least that's what Kodama thinks.)
This is dream come true for Kodama, but his poor "Conscience" is going to have to find a way to keep his host in line so he doesn't do something he'll regret.