The second rising of the reincarnated strongest sage, the opening of the adventure! Siegfried, the grand hero of the Great Sage, is deprived of his position, honour, and power by the guilty tactics of Gilbald who was his right arm. He is expelled to the Forest Without Return, where he has a fateful encounter with a dying vampire girl. He who sacrificed himself and dedicated his blood to a girl - transformed into a vampire and rejuvenated into a boy! He who regained infinite magical power and acquired the special abilities of the vampire was named "Zero", and vowed revenge on Gilbald along with the vampire girl. "It's bad, it doesn't matter a hundred before infinity" - the heroes who once gathered for the great war​ forced to run up from "Zero" this time!

“I have a girlfriend!” Tired of being forced into marriage with my non-blood related younger sister, I told her a lie. Without any moment to lose, I rushed to plead the raijuu Sakurai, the perfectionist Senbongi, and my childhood friend Hotaru for either one to form a fake relationship with me in order to create an alibi. Just when I thought I could take a breather... Eh? All three accepted my request!? In addition to the scramble to vie for me, my sister noticed something amiss and strengthened her surveillance!? Let the romantic comedy between my fake lovers that's full of mistakes commence!