Isekai Tensei, Aibou wa Cheat Mochi no Youjo Nandesu kedo!?

A young man with a tough exterior and a gentle nature rescues a girl from troublemakers but is involved in a car crash. Upon regaining consciousness, he discovers he has entered the enigmatic "Shadow World," a space between life and death where shadows manifest as formidable Shadow Beasts. Finding out he is still alive, he begins a journey with his shadow, which takes the form of a young girl, seeking a way back home. As they travel, he gets entangled in the region's conflicts and encounters unforeseen threats.