Kikan shita Yuusha no Gojitsudan

Kashiwagi Yuuya, a college student, was summoned to a different world as a hero. He’s had his fair share of hardships, but with the help of his faithful comrades, he defeated the Demon King and the Evil God and now returns to modern Japan. And then, everything that happened back there was supposed to become just a distant memory... But he's still the invincible hero he was on the other side, with all his spells and items?!

(Source: Manga UP!)