Within the planet Oukoku, the King summons his vassals to his throne room for an emergency meeting about what has been going on in the last few days. When the king fell ill, the vassals tried to figure out who will be the successor. It devolved into a squabble between two factions lead by Nes and Dan; Nes chooses the kind and animal-loving Prince Hata to be the next king while Dan chooses the political and battle savvy Prince Barkas. But Barkas is not in line for succession unlike his brother Hata and the reason for this, Nes mockingly reveals, is his tiny forehead antenna. The Chidanneksko, or Chinko, symbolizes a male Oukokuan's worth; the larger the Chinko, the more superior the male is. Plus only males with large Chinkos are qualified to be king since a lack of talent can be disguised but nothing can alter the antenna's size.
Dan, who also has a small antenna, tries to argue against the tradition, pointing out that it easily allows fools to become king. Nes poorly tries to deny this by using the king as an example and their arguments causes the king to collapse again. As he is taken away Nes and Dan asks who does he choose to rule and the dying elderly man only responds the capable one with the huge chinko. Later, Barkas and Hata stand in front of their father's grave; Barkas remarks that the king's last words were about their older brother, Dragonia. He had a very long chinko and was highly intelligent, thus he would have been a great ruler. But his super long antenna caused his own death when it was caught by a root, flinging him down a cliff to his demise. Hata proclaims that Barkas would have been just as great if it wasn't for his chinko. Barkas tells his younger brother that Hata is better suited to rule in this time of peace, but Barkas' own existence might threaten it due to this succession crisis. He tells Hata to be a king that loves all creatures before leaving.
Hata awakens from the dream/memory to find himself still in Katsura's choke hold after falling unconscious. Katsura is surprised that he resorted to creating a large ark to save Earth's animals due to his love of them but retorts that there were beasts that even the prince can't handle. He demands that the Oukokuans bring their entire army under Hata's orders to stop the Liberation Army; Sakamoto realizes that Katsura was trying to create an alliance with the Amanto. Over Hata's protests, Katsura remarks that being one of the largest armies in the universe, they will be a show of force to the Liberation Army to say they were the Earth's allies as well as a distraction for Katsura's group so they can quietly capture the Army's base. Hata continues to protest that his people may be wiped out and he didn't care for the planet itself then blames Jii for bringing the Jouishishi here. Jii vindictively orders the guards to shoot the humans along with Hata but finds himself grabbed and placed in a choke hold by Hasegawa, who threatens to harm Jii if they harm Katsura and Hata. He admits to the surprised Katsura that despite being the "underdog" even he was able to make it here. Hata and Jii squabble and blame each other for their predicament and command the guards to kill the other.
The guards are shot and killed by other guards lead by Dan. Katsura and Hasegawa quickly let the prince and Jii go before Dan's men shoot at them all. Sakamoto desperately calls out to Katsura through the speaker button after hearing the gunshots while Shijaku angrily listens on. Dan declares his intent to finally kill Hata and Jii, actually Nes, for banishing Barkas and being unfit to lead despite their larger antennae and make their world fit for his smaller chinko brethren. He also admits that it would be a bad idea to ally with the Earthlings lest their planet be annihilated. As Shijaku asks Sakamoto for the speaker button, Dan asks Hata why dispite expelling his older brother, he never took the throne as king and remained a prince. Suddenly Shijaku speaks up, stating that there was a king, Dragonia, though he died. He repeats Hata's words, that both the capable Barkas and the large chinko'd Hata will work together as Dragonia, so he will remain as prince and wait for his other half's return. Shijaku then pulls off his headband, revealing his small chinko, and demands that Dan stand down as since he, Barkas, has revealed himself, the brothers are whole and they, Dragonia, the King has returned.