She Professed Herself Pupil of the Wise Man (Light Novel) Vol. 9

Suspecting the oni princess who ruled over the defeated Chimera Clausen was the offspring of a high-level demon, Mira entrusts Kagura with the investigation. Meanwhile, the pint-sized summoner returns to Solomon to make her report...and get a little R&R with Mariana! But when the investigation reveals the demon mastermind is now after the Oni's Sealed Casket, Mira, along with three other Wise Men, must rush to thwart the enemy's schemes once again...