No-Late Day is a day where No-Star students cannot be late to class, or they risk expulsion from the academy. Participants have to survive through 999 obstacles, which include numerous varieties of traps, which only the most determined students can overcome.
As the school distributes Goku Uniforms to what they consider capable and loyal students, those that have proven themselves in the eyes of the Student Council can wear one. This event was established to help separate the weak from the worthy, those that remain can be considered more likely candidates for the uniform.
The Trap Department is a subdivision of the Student Council's Disciplinary Committee and is in charge of developing traps for the No-Late Day. It was lead by Maiko Ōgure before she was expelled from Honnōji Academy by Ira Gamagōri for treason against Satsuki Kiryūin.