Houkago wa, Isekai Kissa de Coffee wo Have a Cup of Coffee at the Cafe in Fantasy World, After School.

Synopsis

Yuu found himself in another world, where now he spends his time not adventuring in the town's labyrinth, nor hunting down a demon lord, but running the world's only café. His days pass as he hopes for an upswing in popularity and works towards keeping his... eccentric regulars happy. One day, a student attending the town's magic academy finds his café when looking for a quiet place to study... (Source: Novel Updates)