Shachiku-senpai wa Yutori-kouhai ni Sakaraenai
社畜先輩はゆとり後輩に逆らえない · しゃちく せんぱい わ ゆとり こうはい に さからえない
est. Rough estimate based on volume count, reprints and magazine — not an official figure
Overview
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: AniList
External databases: MADB · AniList
How to compare editions, collected volumes and ISBNs / Sources, updates and corrections