Kikanshita Yuusha No Gojitsudan

one day, your average joe university student, kashiwagi yuuya was summoned to another world by a stupid goddess. his mission isto do what any cliche isekai mc does; become the hero, get the harem, defeat the demon lords, save the kingdom/other earth and go back to earth. after doing all those menial shit, he was granted to go back to his original world with only a second passed despite wasting 3 years in his “hero” life.expecting himself to be an average joe again, much to his surprise, he still retains his powers as a hero. it seems his mission is just not over yet.it's an isekai but not an isekai but technically an isekai? just read it to find out!