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 to pave the way for Nintendo’s own Famicom Detective Club series. Unfortunately, outside of Japan, Portopia has mostly been known for Square Enix’s attempts to revitalize the game entirely using AI for a maligned 2023 remake. Not content with leaving the AI experiments solely to other people, Horii himself decided to try “developing” 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 the titular 72-year-old suspect Komiya for a possible safe robbery. Due to the suspect’s constant lies, the player must use various lines of questioning the game provides to uncover the truth underneath them, all while balancing Agitation and Resistance meters. They rise and fall based on your questioning and may lead Komiya to no longer provide answers at all if they reach their maximum of 100.
その昔、PCで『ポートピア連続殺人事件』を作った時は、自分で物語を考え、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、ＡＩ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. “Back when I made The Portopia Serial Murder Case on PC, I had to come up with the story myself, draw the art, write the code, and create everything by myself,” Horii wrote in his post. “Now, with AI, even if you can’t draw, or you can’t program, you can create a game by yourself simply by asking the AI to do it for you. It’s incredible.”
The director has made no secret of his love for AI in recent months. The Chrono Trigger co-writer has published many social media posts praising it, including celebrating the idea that the technology “hardly ever” makes things up anymore. This has all happened alongside the Dragon Quest series itself being associated with a number of generative AI promotional stunts throughout Japan in partnership with Google’s Gemini.
Currently, Horii is working on the scenario for the latest game in the Dragon Quest series, Dragon Quest XII, which underwent a major reboot in the past year. His historically significant Portopia Serial Murder Case game, meanwhile, looks set to receive a developer- and artist-driven remake courtesy of G-Mode next year.