Following the events of its inaugural season, Mashin Eiyuden Wataru returns for its second installment. Wataru and his friends have been living peacefully on Earth after defeating Doakudar. However, their idyllic existence is shattered when Ryujinmaru appears and implores Wataru to fight again. As it turns out, Doakudar's brother has seized control of the 7 Stars Mountain, the origin of Mt. Soukai's rainbow light. The absence of such radiance would result in eternal darkness for the entire world. Wataru must journey through the 7 stars system once more and defeat his mightier enemy to avert a dismal fate for humanity.