Yusei Matsui (松井優征, Matsui Yūsei) is a Japanese manga artist. He was an assistant of Yoshio Sawai, the manga artist of Bobobo-bo Bo-bobo. He wrote and illustrated the manga series Neuro: Supernatural Detective, Assassination Classroom, and The Elusive Samurai.
Source: “Yusei Matsui”, English Wikipedia (CC BY-SA 4.0), excerpt