Key Person of Interest Detective (重要参考人探偵, Jūyō Sankōnin Tantei) is a Japanese manga series by Murako Kinuta.

One day, he goes on a photo shoot for work with fellow models Itsuki Suo and Simon Toma, where they find a dead body.

[9] Koyama himself felt difficulties because it had been a long time since he had acted in a drama, but he was able to interpret the role well when the director asked him to "feel like a real person".

Although the director, Renpei Tsukamoto, gave only minimal instructions regarding the modeling agency "Wave," where the film takes place, it was created by the art staff with a "mid-century American feel" in mind.

[13] Mirai Shida, who played the role of Natsu who supported Tamamori's character Ken in that drama, made a guest appearance in the second episode of the film as the actress Yuri Otohara.

Several years later, Kei is the first one to find a dead body at a watchmaker's party he attends for work with fellow models Itsuki Suo and Simon Toma , and is reunited with Karin, who shows up at the scene as a detective.

However, after being the first person of interest in a series of murders, Karin is ordered by her boss, detective Manabu Toichi, to keep an eye on Kei as much as possible, even on days when he is off duty.

The DVD and Blu-ray, which also includes over 113 minutes of bonus footage such as a roundtable discussion among the four main cast members, a production announcement press conference, and making-of featurettes, were released on June 6, 2018.