After succeeding in their winter conflict against Taiju Shiba and his Black Dragons, the Tokyo Manji Gang absorbs their group's remaining members. Due to his heroic courage and indomitable spirit, Takemichi Hanagaki should have accomplished his goal of defeating the tragic fate awaiting his girlfriend, Hinata Tachibana. In reality, Takemichi's troubles are far from over. Although Takemichi's actions have exposed Tetta Kisaki's treachery, the conniving schemer has found power elsewhere: Tenjiku, a dangerous gang led by the enigmatic Izana Kurokawa. Izana sets his sights on Manjirou "Mikey" Sano, pursuing a vicious interest in the Tokyo Manji Gang's aloof leader. In the future, Takemichi discovers that the machinations of Izana and Kisaki led to Mikey's moral ruin—a downfall that directly results in Hinata's death. Unfortunately, a terrible loss robs Takemichi of his time-leaping ability, stranding him in the past with one final chance to rescue everyone he loves.

The story follows two individuals who leave their birthplaces behind in search of a new life, traveling through a mysterious warp gate that connects Japan to the world of Euthania. There, in a land rich in nature and home to magical races inspired by South East Asian mythology, they embark on a journey to find a place where they truly belong.

Middle school student Satomi Oka ought to be proud that his choir group placed second at a national competition. However, he views this achievement as a failure caused by his inadequacies. Furthermore, since graduation is fast approaching, his time as leader of the choir is coming to an end. While Satomi is preoccupied with his inner turmoil, a smooth-talking gangster named Kyouji Narita approaches him and requests him as a singing teacher. Every year, Kyouji and his colleagues participate in a karaoke competition, where their boss personally designs a tattoo for the loser. To avoid such cruel and unusual punishment, Kyouji asks Satomi to help him find the best song suited for his vocal range. Albeit reluctantly, Satomi sets his fears aside and agrees to join Kyouji at his karaoke practice sessions. But it remains to be seen whether the mismatched duo will overcome their respective obstacles or fail miserably.