Tenchi Forever!

A melancholic, surreal exploration of lost time and fractured identity, where a protagonist's disappearance into an alternate reality forces his companions to confront the possibility of permanent separation.

One day, Tenchi disappears in the forest near his house. Six months later, Ayeka and Ryoko locate Tenchi living in a city, but with a mysterious woman. What's more, Tenchi appears to have aged several years. Whenever Ayeka and Ryoko catch up to him, he disappears into thin air, apparently existing in a fabricated alternate dimension where he has no knowledge of his past.