Yuji Horii, best known for his work on the Dragon Quest RPG franchise, is also known in Japan for creating a murder mystery adventure, The Portopia Serial Murder Case. That game was released in 1983 for PC titles and is credited with helping pave the way for Nintendo’s Famicom Detective Club series. Unfortunately, outside of Japan, Portopia has been known primarily for Square Enix’s attempts to completely revitalize the game using AI for a maligned 2023 remake. Not content with leaving the AI experiments solely to other people, Horii himself decided to try to “develop” his own spiritual successor using Claude. That game is called Komiya in the Interrogation Room, and it’s a short browser-based experience that takes place entirely within the confines of the interrogation of 72-year-old suspect Komiya for a possible safe heist. Due to the suspect’s constant lies, the player must use various lines of questions provided by the game to uncover the truth beneath them, all while balancing the Agitation and Stamina meters. They go up and down based on your questions and can lead to Komiya not providing any answers if they reach their maximum. 100.考え、絵も描いて、プログラムもして、ひとりでゲームを作りました。そして今、Ａ Ｉを使えば、絵を描けなくても、プログラムしなくても、ＡＩに指図するだけで、ひとりで、そこそこのゲームを作れてしまいます。ホントびっくりです。… — 堀井雄二 (@YujiHorii) October 11, 2026 According to the director’s social media post sharing the game, he only spent about 30 minutes creating it using Anthropic’s AI tools before sharing it, praising the benefits of the technology in game development. “When I made The Portopia Serial Murder Case for PC, I had to come up with the story myself, draw the art, write the code, and create everything myself,” Horii wrote in his post. “Now, with AI, even if you don’t know how to draw or can’t program, you can create a game yourself just by asking the AI to do it for you. It’s amazing.” The director has made no secret of his love for AI in recent months. The Chrono Trigger co-writer has made many social media posts praising it, including celebrating the idea that technology “almost never” invents things anymore. This all happened alongside the Dragon Quest series itself partnering with a series of generative AI promotional stunts across Japan in partnership with Google’s Gemini. Horii is currently working on the scenario for the latest game in the Dragon Quest series, Dragon Quest XII, which underwent a major reboot last year. Meanwhile, its historically important game Portopia Serial Murder Case will receive a developer- and artist-driven remake, courtesy of G-Mode, next year.
