From justpeachyicedtea :

Fooling around as always, he kisses a random guy walking by. But as a result of that, something unexpected happens!!?

Touru lost his parents at a very young age and had been living with his grandfather ever since.
But while his grandfather is recovering from a surgery, he suddenly opens up to his grandson that he will inherit his entire fortune when he dies.

Now his relatives who weren't close with him, started pushing themselves so they can be his guardian.

"Organize that family meeting of yours on Saturday the 10th, it might just be your lucky day" said Tsukitani-sensei his teacher.
Touru has no choice but to believe in those words.

From justpeachyicedtea:
He’s always been by my side, and that was as natural as breathing to me. I’ve never imagined otherwise. Even from now on…

Mikeya Arata, single, works everyday in the university co-op program. His main job is the maintenance of computers. When he finishes his job, he goes straight home and sleeps; and everyday is a repetition of that. But after he is romantically confessed to, this routine of his is on the verge of collapsing. He would doubt his partner’s feelings due to his lack of self-esteem, but now….