Abuto's mother, Shirayuki, came to the Ōmiya Railway Museum, where an event related to the "Railway Day" is being held. After receiving a message for Abuto from Shirayuki, Shin tries various methods to get in touch with Abuto.
As droves of guests come to the Railway Museum for the Railway Day event, Abuto's mother, Shirayuki, also appears. Shin and Sogō are both startled and unsure of what to say when she asks where Abuto is. But Sogō does decide to tell her formally, along with Shima, admitting he was supposed to have done so already. To their surprise, Shirayuki is understanding of what happened, stating that she always believed Abuto might take after his father. She also believes that Abuto will return.
As Shirayuki leaves, Shin follows after. He swears to her that he'll bring Abuto back to her, with Smat offering to do the same. Shirayuki thanks them, and also explains to Shin about the food she'd been carrying. It's Sadamitsu's Power Mochi, a specialty of the Usui pass which was Abuto's favorite as a kid. She explains that the family would always go to Railway Heritage Park on Railway day and buy some to eat. Shirayuki had of course brought the mochi to give to Abuto, but decides Shin should have it instead. Shin is surprised by this. Shirayuki also asks Shin to tell Abuto that she's doing fine when they meet. Shin agrees and again assures that he will find Abuto, as the guy who's going to challenge the mysteries of the world. Hearing about his love for mysteries, Shirayuki decides to tell Shin one more thing. That is, the true identity of Abuto's father.
Meanwhile, Abuto remains in prison, worrying about how he'll protect his parents from the other Teoti.
Shin goes out that night, attempting to communicate telepathically with Abuto. He read about the technique in Mu magazine. He even tries to communicate with the spirit world, but Smat points out that Abuto isn't dead. Regardless, neither of these methods prove helpful. Shin still believes that they should be able to communicate, prompting Smat to ask what he would say if he did manage to reach Abuto. Shin has to stop and think about this, as he gazes into the stars. Then, he asks if Smat can call Abuto's Z Gear. He says that he's tried, but it's out of service. Shin asks to try again, just to leave a voice mail. He then explains to Abuto that his mom came to visit, and told him his dad was a Teoti. He asks Abuto to please reply, as he has a lot he wants to talk about.
When Hanabi and Taiju learn that Abuto could be an alien, they're both immediately stunned and unsure of whether to believe it. Shin admits that he was also skeptical, but points out how Abuto couldn't drive a Shinkalion, unless it was the Teoti's Dark Shinkalion. That makes it possible he is part Teoti. Shin also expresses his desire to meet Abuto again in person and find out exactly what's going on. Shima then comes into the room, implying that he'd already known about Abuto's father. He says that the adults have been working the whole time to come up with a way to have dialog with Abuto. This has led them to testing a new model of Shinkalion at the Nagoya Branch. He invites the drivers to come and see it.
Shin and the others get to see Doctor Yellow, the legendary Shinkansen Ryūji once drove. They're surprised to learn that the driver this time is Shimakaze. It's also revealed that the Doctor Yellow is now equipped with a deep subterranean inspection apparatus. Genbu and Hibiki come to explain this in more detail. Because the Teoti have been trying to destroy Blackstones, Hibiki theorizes that there is likely undetected Blackstone underground in locations where Giant Monstrous Beings appeared. All these locations are connected by the Shinkansen tracks. Now, with Doctor Yellow, the possibility exists of finding the Blackstone before the Teoti, as well as meeting the Dark Shinkalion and Abuto by extension.
Shimakaze departs from Nagoya Branch toward Hakata. He first picks up a reaction in an underground chamber near Meiji Village, where Huge Turtle appeared. More reactions are found near Maibara, Mt. Hiei, and Mt. Homan. Shimakaze returns to Omiya, revealing that reactions were also found near Yokokawa and Ueno Park. Ryūji requests that Sogō begin an investigation in those two locations, which he agrees to. The E6 and E7 are still undergoing repairs, so only the E5 and Doctor Yellow are sent out, the two splitting up. Shin requests to go to Yokokawa, so Shimakaze is assigned to Ueno. Sogō warns that they must return if it's dangerous, however.
On the way to Yokokawa, Shin admits that he picked that location because he believed Abuto would go there. Both Shin and Shimakaze transform their Shinkalions once they've reached their destinations and a capture field is launched.
Shimakaze, meanwhile, discovers a mark indicating that the Blackstone under Ueno was already destroyed. He's suddenly attacked by a Giant Monstorus Being, which Ryūji says is called Horrid Blossom. He explains that the core is in the lower abdomen, so Shimakaze focuses his attacks there. Although he quickly defeats it with Doctor Yellow's great ability, Shimakaze becomes worried for Shin, if the enemy set up an ambush. Abiko tries to send a warning to Shin, but is unable to reach him. Communications were lost on both ends, as Shin is unable to inform headquarters when he locates the Blackstone. Suddenly, the Dark Shinkalion appears before Shin.
In the episode
- Shinkalion Z Doctor Yellow makes its full debut after its brief appearance in its Shinkansen mode in episode 19.
- Horrid Blossom make its return from the previous season.
- This is the first episode to feature Terminal ~Where We Should Be~ as the ending theme.
Note: All characters are listed in order of their first appearances in the episode.
- Shin Arata- Minami Tsuda
- Shimakaze Anjō- Yūma Uchida
- Hanabi Ōmagari- Yuka Terasaki
- Taiju Togakushi- Michiko Kaiden
- Smat- Jun Fukuyama
- Saijō Sogō- Kōsuke Gotō
- Goichi Shima- Takahiro Fujiwara
- Ryūji Kiyosu- Ryota Osaka
- Shirayuki Usui- Chika Fujimura
- Genbu- J. Maxwell Powers
- Kasumi Abiko- Sayaka Senbongi
- Misaki Ōishi- Satomi Moriya
- Nagara Anjō- Nao Tōyama
- Hibiki Mishima- Nodoka Hasegawa
- Minori Sanjo- Wakana Minami
- Suruga Hamamatsu- Ryota Iwasaki
- Abuto Usui- Akari Kitō
- Kannagi- Yōhei Azakami
- Astrea- Marina Inoue
- Z Gear Announcements- Bonji Jinbo
- Script- Kenichi Yamashita
- Storyboard- Akira Tsuchiya, Koichi Ohata
- Episode Director- Yūzō Sasaki
- CG Episode Director- Koichi Ohata
- Animation Director- Natsuki Watanabe