The manga is a what-if story, depicting various Z/X characters living in peaceful school live.
- Asuka-kun - Transfer student and the main character.
- Ayase-chan - Committee chairman of the high school.
- Chitose-chan - High school student.
- Mikado-kun - The super genius high school student.
- Soma-kun - High school student and a lone wolf. Member of the breeding committee.
- Misaki-chan - High school student and the school idol.
- Azumi-chan - Middle school student with weak constitution.
- Nanao-chan - Returnee kunoichi.
- Sakura-chan - Committee chairman of the middle school and Yachiyo-chan's twin.
- Yachiyo-chan - Sakura-chan's twin and the older of the twins.
- Nina-chan - Russian girl with Argentine nationality.
- Shana-kun - Male student that able to use the girl's locker room.
- Sera-chan - Violent, yet naive, elementary school student.
- Kasuga-chan - Mikado-kun's younger sister.
- Honome-chan - Genius transfer student that consider herself as Mikado-kun's rival.
- Reia-kun - Committee chairman of the elementary school.
- Suguru-kun - Solitary elementary school student.
- Kisara-chan - Z/X School youngest student.
- Yamato Sensei - High school teacher and Asuka-kun's older brother.
- Fierte Sensei - Middle school teacher.
- Crepus Sensei - Elementary school teacher.
- Rigel Sensei - Teacher in charge of school infirmary.
- Izumo Sensei - Z/X School deputy head teacher.
- Wyvern Sensei - Z/X School headmaster.
- Vinka-san - Homunculus created by Honome.
- Lawrencium-san - Cardboard Fortress created by Reia-kun and co.
- Garmatha-san - Z/X School janitor.
- Phosflamme-san - Chicken-like creature raised under the breeding committee. Sakura-chan's favorite.
- Almotaher-san - Chicken-like creature raised under the breeding committee. Yachiyo-chan's favorite.
- Maine Coon-san - Nina-chan's pet cat.
- Z/X School (Japanese)