Gitai Saimin

A studious high school student named Ren is killed in a traffic accident and reincarnated into a fantasy world—but as a sword! He wakes up in a dangerous forest filled with monsters and is rescued by a young girl named Fran, who has just escaped from slavery. Together, Ren and Fran embark on a perilous journey to become a legendary hero, with Ren now functioning as Fran's powerful magical sword.