Detective Xeno and the Seven Locked Murder Rooms

Detective Xeno and the Seven Locked Murder Rooms (探偵ゼノと７つの殺人密室) is a manga written by Kyouichi Nanatsuki and drawn by Teppei Sugiyama. It began its serialization in the Weekly Shōnen Sunday manga magazine November 29, 2017.

Plot
A man with no past, memory, or name... They call him Detective Xeno. A man who solved a murder the moment he woke from a coma in a hospital. He, along with his assistant D-zaka Eila, set out to find the mysterious "locked murder rooms" created by famed architect Kai Shichirou.