Moto Saikyou Boukensha no Rojiura Café Nonbiri Kaigyouroku

Café Sirius, operating quietly in a corner of the royal capital, is so empty inside that it's a wonder it hasn't gone out of business. However, the café's master, Gilbert, is actually a former strongest adventurer who accumulated a vast fortune—and he has absolutely zero interest in making a profit from the café?! Despite such a lackadaisical business approach, customers who fall in love with the delicious food and cozy atmosphere start frequenting the shop, and the inside of the café gradually becomes lively... A daily comedy, filled with laughter, tears, and occasional battles, brought to you by a former strongest adventurer who defeated the Demon King to save the world, and a bright, hardworking girl, both harboring their own secrets!

(Source: Kadokawa, translated)