Mushoku Tensei: Jobless Reincarnation Part 2

Suddenly, Eris disappeared, leaving behind a letter. Rudeus thought that he was able to start his life over again and change through various encounters and journeys, but the shock of losing Eris made him withdraw again like he did in his previous life. Just when he is about to give up on everything, the memory of his mother Zenith comes back to his mind. (Source: Mushoku Tensei Wiki)