A student at Takashiro High School, he falls in love with Karin. Their first meeting happens on a bus. When Karin accidentally drops her book, he and his friends visit her school to return it, inadvertently getting involved in a "Goukon" (group date) that includes Karin, Yuka, and his friend Tohru. He supports himself through various part-time jobs as he lives away from his family due to conflicts with his father. His passion for photography is evident, having won several prizes.
Despite Yuka's persistent attempts to attract his attention, he remains unaffected by her advances, often leaving her with Tohru while he spends time with Karin. By the end of chapter one, he shares his first kiss with Karin. Subsequently, much to Karin's surprise, he frequently hugs and kisses her. He consistently appears around her, offering to take her to dinner and escort her home. It frustrates and angers him when Karin, out of habit, disregards her own safety, such as walking alone at night.
Karin initially rejects him because she fears upsetting Yuka, whom she considers a friend. She tells Kiriya that she doesn't like him. However, towards the end of the series, he proposes to Karin, and they get married.
