Ryosuke Tsuji, a male employee feared throughout the company as a demon boss. His subordinate, the easygoing female employee Kokoro, endures his strict daily guidance. But in secret, the two are actually dating. While Ryosuke is ultra-stoic at work, at home alone together, he becomes her tsundere boyfriend who spoils her rotten. Beyond them, two other couples exist within the company, each with their own unique way of relating.