Shikabane-Gatana

the “battle action” manga centers on tsuranuki tsutsuki, a middle school boy who lives a happy life despite slightly strange family circumstances. but when a great disaster strikes, strange zombie-like creatures kidnap his younger sister. to find the whereabouts of his younger sister, tsutsuki heads to monster-infested tokyo, and there has a chance encounter with a high school girl wielding a mysterious sword. (source: ann)