Koi seyo Maou, Ai seyo Yuusha

Yuta Osanai is not just an ordinary high school student... but a (former) hero who transmigrated and saved another world! When Yuta returned to the modern world, for some reason, the Demon Lord that Yuta defeated appeared, too.......? From Twitter! A fantasy love-comedy between a hero (♂) and a demon lord (♂) that begins after their reincarnation back to our world...?

(Source: Kadokawa, translated)