Quick answer — Yuusei Matsui worked on Assassination Classroom Second Season (Original Creator), Assassination Classroom (Original Creator), The Elusive Samurai (Original Creator) and 8 more anime.
Yuusei Matsui worked on Assassination Classroom Second Season (Original Creator), Assassination Classroom (Original Creator), The Elusive Samurai (Original Creator), Ansatsu Kyoushitsu 2: Kagaijugyou-hen (Original Creator), Assassination Classroom the Movie: 365 Days‘ Time (Original Creator), Assassination Classroom the Movie: Our Time (Original Creator), Assassination Classroom: Meeting Time (Original Creator), Neuro: Supernatural Detective (Original Creator) and 3 more.