|School||St.Tachikawa Girls School|
|Class and Year||2-?|
|Club||St.Tachikawa Girls Game Creation Club|
Ōtsuka is second year student at St.Tachikawa Girls School and member of St.Tachikawa Girls Game Creation Club, during Hashimoto Adventure Island Tournament she with her other members club then makes one of culprits by cast as mysterious abductor masked.
She is also member of St.Tachikawa Girls Fencing Club.
- Just like other characters' in D-Frag! their names are reference to railway stations in Japan, Her name is derived from Ootsuka Station.