Hiroto and Kazami have made a small but very important improvement in their relationship. However, the Build Divers and the Resistance are now overwhelmed by the attack of the mysterious Gunpla known as "Seltsam." The pendant that Muran entrusted to Hiroto and the others seems to become a key to turn the tide, but… Meanwhile, May begins gathering intelligence at Magee's bar.
Leave it to us. We'll take care
of the underwater monster...
دعوا الأمر لنا. سنتولّى أمر الوحش
...تحت الماء
Überlass das nur uns. Dieses
Unterwassermonster werden wir im Nu …
Por supuesto.
Acabaremos con el monstruo en el a…
Por supuesto.
Acabaremos con el monstruo en el a…
Laissez-nous gérer !
On va vous défoncer le mon…
Ci pensiamo noi! Faremo subito fuori 
quel mostro che si nasconde sott'acqua!
Pode deixar conosco, logo cuidaremos
do mundo debaixo d'água—