both are bmsg audition shows and the process of forming a group is relatively similar, although missionx2 follows the story of mazzel being formed after the lineup was revealed to the public already.
Both series are audition programs that follow the formation of a boy group under BMSG. Throughout the course of the show you see multiple performances of original songs and the development of the skills of the trainees.
Missionx2 is BMSG's second audition show, the one happening right before The Last Piece. Although the show is mostly focused on members chosen to debut in MAZZEL, we also meet Kanon here and find out more about his story before The Last Piece.
