|Birthday||December 13 (Sagittarius)|
|Likes||Salmon, The sea|
|Role||Trombone Player, Trombone Leader|
|School||Rikka High School|
|Occupation||Student (Third year)|
|Light Novel||Rikka Novel vol.1|
Mirai Sezaki (Sezaki Mirai) is a character from the spin-off novel. She is a thrid-year trombonist and the trombone section's leader of Rikka High School Concert Band.
- It is possible that Mirai is a girl who talks with Azusa in Hibike anime S2 episode 5.