>>528761470
Not those anon, but she appears everywhere in the most random story part.
>vol 3, ark group in vol F
>Main group of an event (nyGehenna)
>Cameo in a lot of events (sports event, trinity idol, summer gehenna, dHina event, etc)
>Multiple group stories
If you go by appearance, Haruna is up there.
Also, first student to have 2nd alt