Mushuko Stories

After a 34-year old NEET gets hit by a truck, he wakes up wounded in a fantasy world. He is then taken in by the Greyrat family who give him his first job of watching their son Rudeus. Meanwhile, he begins to study magic and vows to do better in this world than in his last. But how can you succeed in a world you don't belong in? (AU where the MC and Rudeus are separate characters.)