Sudachi no Maoujou

The heroes have defeated the Demon Lord and the world is finally at peace - but Murabito, a boy from the village of Saisho, was in trouble. The reason is that the world is so peaceful that his weapons shop no longer has any customers at all! If things continued as they are, the shop will have to close soon......and then a girl appeared.......

(Source: Magapoke, translated)