She Professed Herself Pupil of the Wise Man (Light Novel) Vol. 14

BACK TO SCHOOL With Artesia successfully accounted for, Mira returns to Lunatic Lake for a well-deserved break from her hunt for the missing Wise Men. There she runs into Emilia, a student obsessed with the legendary Danblf, and decides to take the girl under her wing. But when graffiti is found on a portrait of Danblf, Mira is too furious to stand by. She disguises herself as a student and brings Emilia along to seek the culprit!
Series Overview: Sakamori Kagami was one of the top players in the VRMMO Ark Earth Online as Danblf, a veteran summoner with the gravitas to match his elite status.
When he falls asleep playing one day, he’s transported to a world where the game is reality—but instead of his all-powerful avatar, he’s stuck in the body of a cute young girl! He can’t let anyone know that this little cutie is really Danblf, so he takes the name “Mira” and claims to be Danblf’s disciple. If this gets out, he’ll never live it down!