Warning: the following contains spoilers for The Night Beyond the Tricornered Window, Episode 9, “Confluence”, now streaming on Crunchyroll.
The Night Beyond the Tricornered Window is not a character study of Mikado Kosuke, but of Hiyakawa Rihito, one of the strangest characters in anime. He doesn’t understand human emotions or societal norms. The viewers need Mikado because Hiyakawa is not relatable. No one had been through what he had, and Mikado’s perspective provides a window into Hiyakawa’s psyche since Mikado is the only person he trusts. But what will become of Hiyakawa if Mikado’s not there?
In some respects, Hiyakawa is still a child trapped in an adult’s body. He has a hard time understanding and expressing his emotions as this episode shows. In other respects, his take on the world is so cynical because of the amount of abuse he experienced. He tends to destroy everything that gets in his way without a second thought. But this is the paradox of Hiyakawa, he cannot express his emotions and therefore no one can truly understand him. But deep down, he craves understanding and compassion, but doesn’t know how to ask for them. This led him to become more cynical as a result.
Mikado represents hope for Hiyakawa, not only because of his power to cleanse negative energy but also because of his kindness towards Hiyakawa. Unlike those in the cult, Mikado simply cares without asking for anything in return, and this is what Hiyakawa wants in his life, even though he doesn’t understand why. However, Mikado’s kindness is in his nature, he cares about everyone, not just Hiyakawa, and this is actually a major hurdle in his and Hiyakawa’s relationship that both have yet to grasp.
This is why when Mikado tries to stop Hiyakawa from destroying “sensei”, Hiyakawa doesn’t understand why Mikado is doing this. In his mind, he is helping to solve a problem. He pushes Mikado into a spiritual tunnel he made back in Episode 3 that leads to a house where people can’t escape once they’ve entered. The house is cursed by the woman who inhabits it. She and Mikado talk about curses and hatred, and the woman eventually lets him go but warns about attempting to take away hatred from people who only have hatred left.
As Mikado is trapped, Hiyakawa heads to the site of his old cult to find “sensei”. They both want to claim to the massive energy of hatred left within the house. It is the energy that sustained “sensei” after he left his family. But, at this point, he is slowly losing his human form due to the energy. Mikado arrives just in time to confront them both, yet he doesn’t know the person in front of him is his father. Mikado’s presence nonetheless breaks his father’s sanity, since he’d been suppressing memories about his wife. The negative energy he’s been saving pours out of him like a flood and is about to consume everything in front of him.
A neighbor comes over to complain about the noise, and Mikado chooses to save him from the negative energy, believing that Hiyakawa is strong enough to save himself. But, he never saw the fragility and the desperation in Hiyakawa's mind. Hiyakawa is shocked that he is abandoned once again by the person he thought cared about him. Feeling hurt, Hiyakawa pushes Mikado away and is now left alone with “sensei” in the darkness.
This is the moment where Mikado realizes that Hiyakawa’s understanding of the world is fundamentally different from his. Their completely opposing personality is what attracted Hiyakawa to Mikado in the first place, but it is also what divides them. This shows that sympathy alone is not enough to save someone from their pain, empathy is what Hiyakawa really needs. Mikado empathized with Erika and this helped her gain the courage to escape, but he never really understood Hiyakawa, and this is their ultimate problem.
