While Chidori is watching a yakuza movie in the student council room, she notes that yakuza always charge in head first without thinking instead of using combat tactics. Ren remarks that that violent way of thinking is just like Sousuke, and explains that using swords over guns is a mark of honor. Sousuke walks in looking very depressed and explains that he made a large investment on a highly advanced weapon that didn’t sell very well. While they and Ren are leaving a snack shop on the way home, the see a fight break out between two yakuza gangs. The losers turn out to be working under Ren’s father Kanji. Ren runs up to one of them, Shibata, and wipes his face with her handkerchief. Shibata explains that the rival gang is the Ryujinkai, who are taking advantage of the Mikihara leader’s illness to start moving in on their territory. Chidori recognizes them as the punks who tried to harass her in the amusement park and threatens to summon Bonta-kun. Shibata apologizes for his actions from before and wants to ask Chidori a favor. At the Mikihara residence, Ren brings her father his medicine and the latter scolds Shibata for getting into another fight and reminds him that his child is now five years old. Shibata tells him that the Ryujinkai is becoming too strong and that they need to hire a bodyguard. He introduces Bonta-kun and Chidori as his interpreter. Kanji thinks this is a prank and nearly dices Shibata, but Bonta-kun throws him into the pond. Kanji acknowledges his strength and collapses.
Bonta-kun starts the Mikihara’s training by having them run a lap around the city, followed by combat tactics. Their progress is slow, however, due to their impulsive behavior and tendency to shout all the time. As the Ryujinkai watches this, they decide to humiliate Kanji by kidnapping his daughter. On the way back from school, Chidori remark’s that unlike the school’s rugby team, the Mikihara gang is too overconfident. Sousuke says that his plan is to strengthen them just enough so that they are just as strong as the Ryujinkai. This way both sides will try to avoid conflict. When they meet Ren, Chidori goes with her while Sousuke leaves to change into Bonta-kun. Sousuke tries to turn off the voice changer but the entire suit deactivates as a result, forcing him to turn it back on. As he exits the public bathroom, he’s approached by Shibata. The gang member escorting Ren and Chidori was attacked and the girls were kidnapped. Sousuke wonders how he can solve the situation without any causalities given the Mikihara gang’s weak state, then gets an idea. At the Ryujinkai’s headquarters, Chidori and Ren are approached by their leader, who plans to use them to force the Mikiharas out of their territory. Just as they’re about to force them into wearing embarrassing outfits, a truck crashes into the building’s entrance. The Ryujinkai members rush out to look for the attackers, and get ambushed by Sousuke and the Mikihara gang, decked out in the mass produced Bonta-kun suits. They quickly take over the building and surround the Ryujinkai’s leader. He tries to hold Chidori at gunpoint but she bites him and Sousuke uses the distraction to dispatch him. When the police station gets word that the Ryujinkai gang was wiped out by Bonta-kun, Yoko goes berserk. Bonta-kun has the gang run back home while the morning news reveals how the Miami police used the recently-bought Bonta-kun suits to thwart a drug smuggling operation.
Wow. Just wow. As if one Bonta-kun wasn’t hilarious enough, Sousuke went ahead and mass produced it for world-wide distribution and put them to good use rescuing the girls using non-lethal means. We also get a silly explanation to justify why Sousuke can’t talk normally in the suit as well as a censored reference to Ambassador Magma, one of Osamu Tezuka’s many characters. It was really nice to see all these continuity nods to events from earlier episodes considering the one-shot nature of each story.