The Hidden Dungeon Only I Can Enter (Light Novel) Vol. 5

Noir and his friends spent the last days of summer vacation saving the town of Honest from a monster siege. Now they get to meet a king! From there, it's back home, back to school, and back to exploring the infinite labyrinth of the hidden dungeon. Noir has a new mission, after all: free his master Olivia from her curse, no matter the cost.