Black Shain no Tensei Saki wa Dom/Sub Universe no Sekai deshita

One day, Mikito collapses from overwork at his exploitative company. When he awakens, he finds himself unexpectedly close to Yanagawa, an elite coworker he barely knew before. He discovers a parallel world where Doms, who thrive on domination, and Subs, who find comfort in being dominated, exist…?! A story of office life and an unexpected connection between a nurturing Dom and a Sub who’s still finding his way!

(Source: Shinshokan, translated)

Note: Includes two extra chapters.