Sergeant Keroro and his four underlings traveled from their home planet, Keron, to overtake Earth. Surprisingly, they found themselves enjoying their new lifestyle on this foreign planet. Though Keroro's original mission was to stay with Hitana in order to carry out the invasion, he became fast friends with Hinata's son, Fuyuki. Today, just like any other day, Keroro joins Fuyuki in the search for his beloved Gundam plastic model. On their way home, they stumble upon a tiny shrine and curiously enter inside. Accidentally shattering a vase, the town is soon thrown into chaos by extraordinary events. Witnessing this, they learn that the vase once held Kiruru - an ancient and powerful weapon from Keron. To their surprise, Mirara approaches and unveils the only way to save Earth. However...