Tenchi Forever(1999)

Tenchi Muyou! in LOVE 2: Haruka Naru Omoi

Tenchi walks into the mountains and disappears. After searching all over Japan for Tenchi, Ayeka and Ryoko finally locate him in Tokyo where he is now several years older. Tenchi appears to be in a parallel world with a mysterious girl, named Haruna, and doesn't remember Ayeka and Ryoko! What is the mysterious connection between Haruna and Tenchi's grandfather, Yosho? It's up to Ayeka and Ryoko to discover what Haruna wants with Tenchi and to rescue him before he disappears forever!

(Source: Geneon Entertainment)