This series focuses on Bowser Jr and his legal guardian member, Maki Nishikino, however, they do not get along.
- Honoka Kousaka
- Rin Hoshizora
- Umi Sonoda
- Eli Ayase
- Nozomi Toujou
- Hanayo Koizumi
- Maki Nishikino
- Kotori Minami
- Nico Yazawa
Super Mario Characters
- Princess Peach
- Princess Daisy
- Princess Rosalina
- Bowser Jr
- The Koopalings
- Koopa Troops goes to Maki's House!: After their castle was torn apart by the Mario Bros, the Koopa Troops find Maki's House and they decide to stay here until their castle is rebuilt.
- Junior and Koopalings goes to FanonTown Burgers!: Junior, along with the Koopalings persuades Maki to take them to FanonTown Burgers, but most attempts fail.
- The Playdate at the Yazawa Household: Maki drops off Junior and the Koopalings on a playdate at the Yazawa Household with Nico, Cocoro, Cocoa, and Cotaro.
- Junior and the Koopalings goes to the Mall!: Junior and the Koopalings force Maki to take them to the Mall.
- The Nintendo Switch!: Bowser Junior and the Koopalings wants to get the new Nintendo Switch! But Maki wouldn't let them, which eventually leads them to persuade her multiple times.
- Bowser Junior plays Hockey!: Bowser Junior wants to learn how to play Hockey.
- Bowser Junior goes Street Racing!: Bowser Junior and the Koopalings hijacks cars and decide to go Street Racing and cause chaos.
- This series might take place after the events of The Misadventures of Nico Yazawa.
- This series was originally going to be called Bowser Jr and Maki Nishikino's Awful Adventures, but it was changed to The Adventures of Bowser Jr and Maki Nishikino.