Shachiku-senpai wa Yutori-kouhai ni Sakaraenai

At the order of his black-hearted boss, corporate slave, Niwa, works overtime every day without a day off. His heart is without rest these days without a cute girlfriend... However, after passing out drunk, he wakes up in the embrace of his easygoing kouhai, Nagase?! Niwa tries to keep his distance from Nagase, but his body has already been exploited by him.

(Source: Takeshobo, translated)

Included one-shots: Yuutousei no Theory, Hirefuse! Senpai Yankee