Tensei shitara Ken deshita

Reincarnated as a Sword, also known as I Became the Sword by Transmigrating (Japanese: 転生したら剣でした, Hepburn: Tensei Shitara Ken deshita), also known as Tenken (転剣) is a light novel series written by Tanaka Yuu and illustrated by LLO.

The novel series was adapted into a manga series by Maruyama Tomoo and published by Denshi Birz.

Plot
When he realized it, the protagonist was in another "game-like" world and had become a sword that was stabbed in the ground in a great forest, overrun with beasts. At least, that was until he met with a cat girl that was about to be attacked by a bear type beast.