From Shinmakoku Scanlations:

Kondou Takayuki hates his boss from the bottom of his heart!! Takagi Toshinobu is mean, heartless, cruel, insensitive... a true sadist! And only to Kondou, by the way! He's perfectly nice to everyone else... WHY? Kondou keeps asking himself over and over again... Then one morning he finds himself in the same bed as his boss. Uwaah... What had happened the night before?

After trying for so long to change himself from the person he was in university and leave behind the painful memory of unrequited love, why does the very person Nakajima wanted to forget the most have to appear before him now?
(Source: MU)