Futari wa Pretty Cure
Working for the Dark King
Kiriya was created by the Dark King to do his bidding, whatever it is. Somehow, he was created in a way that made him the younger brother of another minion, Poisony.
Kiriya is introduced along with the other members of the Dark Zone, insulting Pisard for his failures.
After Gekidrago is defeated, Poisony, Kiriya's older sister, is the next one to confront Nagisa and Honoka, though he decided to infiltrate Verone Junior High School to spy on the girls for the Dark Zone. However, when he first starts to interact with Pretty Cure in their civilian forms, he is surprised to see how Honoka is the only girl until that point to not be swayed by his good looks.
Some members from the soccer club he signs into asks around for help on his grandparents' farm, which he accepts. While on the farm, however, he does not understand why it is so important to help others, and instead lays down. Honoka, who works with him, scolds him and explains why one should help others. She pushes him to try harder, making him silently angry. However, when he falls while pushing the wheelbarrow and gets a cut on his finger, Honoka cares for him and helps him put a bandage on it. At the end of the day, when everything is finished, Kiriya still thinks about the kind things Honoka said to him when Poisony appears.
Realizing that he is starting to think like a human, he agrees to help his sister to defeat Pretty Cure. While keeping a wall separating Cure White and Cure Black, he watches as Cure White gets tortured by Poisony's Zakenna, and accidentally weaken the wall when watching her determination to protect the Garden of Light. Cure Black gets inside and saves her, and after the battle, Kiriya sees how Cure White is kind even to insects.
Being the target of many young girls' crushes, Kiriya is confused about what love is, eventually asking Honoka for advice. She gives him that, but hearing the day after that the person who encouraged a crushing girl to confess her love to him was Honoka herself, Kiriya rips the love letter to pieces in anger. Honoka confronts him afterward about his attitude, but he yells at her and tells her how she does not think about his feelings at all, despite all the confusion he is going through with human emotions. Realizing her mistake, Honoka apologizes and walks back to her classroom with Nagisa just as they get transported to another dimension by Poisony. While having a test, Kiriya things about the confrontation and, knowing that Poisony is winning over Pretty Cure, anonymously saves them before they get killed. After school, he apologizes to the girl from earlier, who tells him that it is okay. He is surprised by her reaction, though they do not interact more from then on.
When Poisony eventually decides to fight with all her power. Kiriya talks to Honoka on her way to Nagisa. He notices a perfume she made during science club lesson, and though Honoka is surprised he knows the flavors she put on, he mumbles that Honoka does not need perfume to be like her. Realizing what he said, he shrugs it off when she asks her, and leaves. Back at the Dark Zone later, he feels Poisony's life being drained. He tells Ilkubo that he chooses to live by following the Dark King, but cries alone as he watches his sister's life force going into the Dark King.
Kiriya, having made his decision to follow his destiny as a descendant of the Dark Zone, tells Honoka who he really is, and tells her to come with Nagisa to fight him. When they meet up, the girls try to talk him out of it, knowing his kind side, but he refuses and attacks them. While they fight, Kiriya realizes his feelings for Honoka, and with her encouraging words that he can change his destiny, gives her his Prism Stone. However, this gesture makes him a traitor to the Dark King, and Ilkubo appears immediately to take him away to meet his fate. Knowing that he did all he could, he accepts it without a fight, despite Cure White's desperate cries.
He is believed to have been killed by either Ilkubo or the Dark King, but his defeat caused sadness for both the girls, and Honoka is revealed the whole night following the event. She is still guilty about his death the rest of the year, and when being asked if she had any guy she was interested in, she was awake half the night thinking about him.
He is mentioned during Verone Junior High School's Christmas party by Kimata and Shougo Fujimura, as they are annoyed that he left without any notice. Unknown to them, this brings back hurtful memories in Honoka, depressing her. He returns shortly in a dimensional rift after a battle to warn Pretty Cure about a future fight. Cure White tries to stop him from leaving again, but is too late.
During the final fight on the Dark Zone, Kiriya reveals himself before Pretty Cure when saving them and helps them hide from the Dark King. He tries to get them to stay hiding, but they surprise him by wanting to fight despite the odds. He eventually lets them fight, and is surprised when they eventually become the winners. However, as he was made by the Dark King, upon his defeat, he also vanishes. As he does so, he believes that there is hope and a possibility to change one's destiny. He has decided for a place he wants to be, but disappears before he can say it out loud.
While Nagisa and Honoka walk home from school, Honoka spots a young boy who has a very similar look to Kiriya, though it turns out that this boy has human parents and is happy with them. Neither does he seem to recognize them, though he stares at Honoka's eyes for a long time. Seeing the boy walk away, Honoka sadly wonders if they will ever see each other again, which Nagisa assures, saying that they are all under the same big sky.
Futari wa Pretty Cure Max Heart
In Futari wa Pretty Cure Max Heart, he is only mentioned, but not shown. Therefore, it is unknown what happened to him after the end of Futari wa Pretty Cure. Although in the last battle he got hit very hard with the dark seeds powers which might of killed him.