NeoBetterfly's manga / #Rejuvenation(1)

48.5 | | | | 3 | 3 | 4 Middle-aged corporate slave ML sneezes himself to death in his sleep after a work marathon and is brought to another world where he is given a second chance at childhood. He first spends years researching slimes in the wild then meets a Duke and his family who take him under their wing.