The cast of characters in Mai Ball!. As the cast gets more massive, each football club has its own page, with other minor characters getting their own page. All characters are Japanese unless otherwise stated, and each of the characters' image colors (if any) is a Shout-Out to one professional or national football club in Real Life, with the exception of The Heroine Mai, who bears the image colors of the protagonist team.
- Kijiyama North (Kijikita) High School Girls FC
- Kijiyama South (Kijinan) High School Girls FC
- Franklin International School Girls FC
- Seirin High School Girls FC
- Kuryuin High School Girls FC
- Other Characters
