By the Grace of the Gods - Season 0

Only 39 years into a life full of bad luck, Ryoma 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 in the forest. But after healing an injured traveler, Ryoma decides to set out with his new friends on a journey to use his power to help others. A whole new world awaits him, where his skills as a magic user and slime tamer continue to elicit surprise and admiration.