Yoake ga Ichiban Kurai

Takaya, an unsuccessful rookie host, forgets his keys one night and ends up passed out drunk in front of his apartment. He is rescued by Saitou, a novelist living in the same building. Gentle and mature, Saitou gradually draws Takaya in, and Takaya finds himself increasingly attracted to him. But...? A poignant story of a novelist haunted by his past and an inexperienced host struggling to find his place—an unforgettable tale unfolding in the darkest hour before dawn.

(Source: Shinshokan, translated)