Fenrir ni Tensei shita Hazu ga Dou Mitemo Shiba Inu: Shiba Inu (Saikyou) ni Natta Ore, Mofumofu sarenagara Kami e to Nariagaru

Tarou, an office worker, saves a wolf-like creature from being run over by a truck and loses his life. When he arrives in another world, a capricious goddess reincarnates him as Fenrir, the strongest holy wolf on the inside and a Shiba Inu on the outside. Taro meets Princess Sophia, who has been praying to Fenrir, believing him to be the messenger of salvation, and sets off on an adventurous journey...?!

(Source: Kodansha, translated)