After defeating the veterans of Seiren Technical College, the Try Fighters win an easy victory in the third round, as their opponents self-destruct! With luck on their side, they are advancing to the quarterfinals. Fumina and the others observe the following match to see their next opponent. The victor of this match is Joto Middle School, which uses straight-assembled Gunpla but defeats a regularly winning team thanks to its fighters’ own control skills. After the match, two members of the Joto Middle School team beg the Try Fighters to let them win for the sake of their team leader Shimon Izuna’s little brother Mamoru, who is battling a serious illness. Fumina and the others are bewildered by this unexpected request, and begin to question their own reasons for fighting. In order to see the situation for himself and test his resolve, Sekai goes alone to the hospital where Shimon’s brother is being treated. Here, Sekai issues a straightforward declaration of war to Mamoru the Gunpla builder, and to his opponent Shimon!