BY THE GRACE OF THE GODS

Only 39 years into a life full of bad luck, Ryouma Takebayashi passes away in his sleep! Taking pity on him, three divine beings show compassion by reincarnating him as a young boy to a magical, new world. Now he spends his time researching and caring for slimes. But after healing an injured traveler, Ryouma decides to set out with his new friends on a journey to use his power to help others. (Source: Funimation) — Description from AniList community (anilist.co).