From Naono Holics:

Melon is clumsy and bad at everything - he knows this much about himself, and he's never let it bother him.

What does bother him, though, is that he has no money, no place to stay, he's quit school, he's hungry, he's in a city he doesn't know well, and it's raining...

And yet, he meets someone who's having an even worse day than him, one Kawai-san, who wastes no time in inviting him up to his apartment for a hot meal and sex.

Melon decides on the spot that he'll be Kawai-san's kept boy! Why not? Kawai-san is rich, and Melon, as it turns out, likes sex with men. But are things between them really that simple...?