Isekai-gaeri no Kyoushitsu de, Maou ga Koishite Gomennasai

It seems my crush has destroyed humanity once before in another world... One night, I finally summoned up the courage to confess my love to my crush Yua, when all of a sudden, a meteor struck me dead, and I was reborn in a different world. However, just as I'd almost accepted my fate as an inhabitant of this new world, I went on to defeat the demon king in mere seconds. I had a world to get back to and a confession to carry out, and used my newly acquired hero's hacking skills to return home! Upon my return, I made my way to my classroom. I opened the door to find that everyone was a returned hero! When I saw Yua, I couldn't believe my eyes... A former demon king in a sea of former heroes...! (Source: Coolmic)