The Seduction Of The Deep Sleeper summary:

Toma Sugawa is a cool-headed, unsociable businessman. For some reason, he's not in a relationship, and he spends his life watching the days go by. One thing that has become a part of his daily routine, is waking up one of the tenants in his grandfather's apartment complex. That tenant is Kaoru Aida. He has countless alarms go off, and still doesn't wake up until Toma comes in to wake him. On top of that, he asks Toma to wake him up the next morning, without a lick of remorse. With an attitude like that, of course Toma is on the verge of snapping. But one day, Toma goes to wake him up as usual, and Kaoru, still sleepy, pushes him down?! Enjoy this clumsy, blooming love story between an inconsiderate guy and a guy still stuck on his ex!+