The Build Divers decide to participate in a Battle-Random mission in which the matchups are randomly determined. Their opponent turns out to be a force called Hyakki, which includes Do-ji, against whom Riku won his first victory, and Ogre, who gave him his first taste of defeat. Riku's heart pounds with anticipation at the idea of assessing his growth by taking on Ogre, using the strength he's accumulated through his previous experiences. Meanwhile, Do-ji's own heart burns with desire for revenge.