In space, a being called Ohboss informs his underling De Butcho that they lost a precious planet energy extractor because of Redlone’s foolishness. Butcho’s mission is to continue searching for the planet energy reservoirs and find out the identity of the Earth robots opposing them. Butcho quickly sets to work and has his computer bring up the locations of Redlone’s encounters with the Brave Fighters. The computer informs him that the first two encounters were in Japan. Hikaru and Da-Garn wake up Seiji and the latter remembers that today he starts sixth grade. As they eat breakfast at Tsukushi, Misuzu announces on the news that investigations are still being conducted into the invaders who were repelled by the unidentified robots during the attack on Los Angeles. The Global Defense Army can’t track the invaders so they remain on full alert. The next news story is about an entire mountain forest that mysteriously withered overnight. Haruo immediately launches into a rant about how humanity’s disregard for the environment is clearly what caused this incident. Later, Seiji and Hikaru run into Hotaru staring at a blossoming cherry tree. Hotaru says that the cherry tree is crying. Hikaru thinks that she’s referring to the petals falling, but Hotaru says that the tree is sad for a different reason before spotting something in the distance and running away. A parade of circus performers passes by announcing the arrival of the Mystery Circus in town. At school, Morisawa introduces new transfer student Pink Yamamoto to the class and has her sit in the empty seat next to Seiji and Hikaru. Despite her awkward speech, the boys fall head over heels for Pink. Hotaru says that she is not feeling well, so Morisawa steps out to take her to the nurse’s office while Seiji explains to Pink that Hotaru often gets sick. The boys immediately begin asking Pink about which countries she’s been to while the girls leer suspiciously. In his ship, Butcho continues to cause more trees to whither so he can power up his armored beast tree Joanna. After school, Pink asks Seiji why the day finished quickly and why they were given so many books. Hikaru explains that those are their new sixth grade school books and classes start for real tomorrow. Pink thinks the math problems in the book are very easy and Hikaru asks if she studied them at her previous school. The trio runs into Joanna curling its branches around a withering cherry tree. Seiji and Hikaru wonder how a tree grew so quickly from out of nowhere, but Pink tells them that this tree is common in other countries and that nothing is strange about it. She then asks if they want to go to the Mystery Circus since entry is free during the grand opening. Back home, Seiji discusses the withering trees with Da-Garn and tells him about the new tree growing near their school. Seiji tells Da-Garn not to worry about the new tree and to message him if anything happens. Pink arrives to take Seiji to the circus and the latter wonders how she back from her house so fast since he hadn’t even gone inside his yet. Butcho orders the now fully grown Joanna to begin the operation and the latter sprouts numerous vines.
At the Mystery Circus, Seiji, Hikaru and Pink are amazed by the inhumanly incredible performance of the clowns and acrobats. The ringmaster comes out and announces that the real surprises are still coming as he unveils an animal act with strange hybrid creatures. Joanna’s vines wrap around trains and cars all over the city to scan their internal structure. When the computer announces that none of the scanned vehicles can transform into robots, Butcho orders Joanna to go on the offensive. Pink excuses herself to go to the bathroom just as the ringmaster announces the star attraction: trapeze artist Magical Pinky. Joanna steals Tadashin’s bike and starts rampaging all over the city. Da-Garn contacts Seiji and informs him about the monster tree attack. Seiji quickly orders Da-Garn to destroy the tree and suits up. He rushes out into the circus ring to warn the audience of the incoming monster attack just as Pinky finishes her act. However, the audience thinks he’s one of the costumed performers and ignores him until Joanna tears through the roof of the tent. Da-Garn quickly rams into Joanna to divert its attention and says that anyone who causes trouble must answer to Da-Garn. Joanna shoots vines at Da-Garn but the latter dodges and cuts the vines with a kick. The vines dissolve into the ground and Joanna shoots out more of them. As the crowd of people evacuates the circus, Da-Garn fires at Joanna with his Da-Garn Magnum. However his shots have no effect and Joanna grabs him. Hikaru frantically searches the circus for Seiji and Pink just as Joanna throws Da-Garn inside the tent. Da-Garn tells Seiji that Joanna is not from Earth. Seiji wonders if Joanna is from outer space while Butcho who is observing the battle wonders who Seiji is. Joanna drops some of the girders holding up the tent and Da-Garn quickly whisks Seiji out of the way. However, Hikaru gets buried under the girders. Seiji has Da-Garn combine into Da-Garn X and Butcho orders Joanna to not hold back anymore. Joanna fires a beam at Da-Garn X but the latter dodges and knocks it down with Earth Vulcans. Seiji hears Hikaru crying for help and his suit allows him to just barely lift the heavy girders long enough for her to get out. Hikaru thanks Seiji for saving her again and asks who he is, but Seiji quickly tells her that it’s dangerous to stay here and they both run out of the tent. Da-Garn X slashes Joanna with his Da-Garn Blade and the latter sprouts more vines and fires another beam. Da-Garn X shrugs off the beam and destroys Joanna with his Earth Cannon much to Butcho’s annoyance. After the battle, Seiji runs up to Hikaru, Pink and Tadashin. Hikaru angrily demands to know where he went because they were scared to death. Pink however remarks that it was a lot of fun. Hikaru wonders if nature is taking revenge on humanity, but Seiji assures her that the monster tree wasn’t even from Earth while Tadashin is surprised to spot his patrol car right next to them. Butcho’s computer finishes its analysis and reveals that there’s a very high chance the Brave Fighters are hiding in the city that Joanna attacked and that the mysterious costumed figure is working with them. Butcho vows to discover the identity of that person and make him pay for what he did.
With the start of the Butcho arc, we’re introduced to several new characters. Butcho quickly distinguishes himself from Redlone by utilizing biological monsters instead of mechanical ones and he certainly didn’t waste time getting started on his mission unlike his predecessor. He’s not without his quirks though, as evidenced by how he affectionately gives his monsters pet names. More importantly, we now have a name for Redlone and Butcho’s master. If mecha anime taught us anything it’s that someone who can make giant projections of their face using lightning isn’t easily trifled with. On the human side we get Pink and the Mystery Circus. While it’s still unclear whose side they’re on yet, Pink disappearing just as Magical Pinky’s act started raises a few suspicions. Da-Garn X gets a new attack here and I like that they’re not overly relying on stock animation for finishing off the monster of the week. I do wish however that the Earth Cannon’s animation wasn’t almost entirely recycled from Granbird’s Gran Cannon attack in Fighbird.