Cheat na Kaineko no Okage de Rakuraku Level Up. Sarani Juujin ni Shite, Icha Love shimasu.

Due to a mistake made by the goddess, my pet cat Misha who reincarnated with me was the one who became the strongest character. Furthermore, she can even speak, and is even knowledgeable of the other world.
The cheat-like Misha used transformation magic and turned into a beastkin (Nekomimi). Together with the Nekomimi young girl (sometime she is in black cat form), this is the story of our slow and leisurely life in the other world.

Note: Includes 2 extra chapters.