Yu-Shibu

Raul Chaser was once the top student at the hero-prep academy, destined to slay the [Demon King]. Then the [Demon King] was defeated by someone else, the hero industry collapsed overnight, and Raul -- with no profession, no skills, and a sister to feed -- reluctantly took a part-time job at Magic Shop Leon, a struggling capital-district magic-item store.

Years later he is still there, ringing up registers and rolling his eyes at his ex-classmates. Then one morning the shop's owner hires a new recruit: Phino Bloodstone, the former [Demon King]'s daughter, freshly out of work for the same reason he is.

A retail-sector workplace comedy starring two people the world no longer needs.