Abunage.

Kuroda, an oblivioys airhead, has a new site foreman: newcomer Akaishi. Kuroda finds him somehow irritating, but he's attracted to Akaishi's beautiful ass, and Akaishi is affectionate towards him... Even though they don't mesh together, they start becoming closer?!

(Source: Original publisher, translated)

Included one-shot: Oomaji. Returns