

Disguised as Shinichi Kudo, Kaitō Kid finally manages to get information about the sapphire that is kept in the underground vault of a mansion. Ran, who does not recognize him, asks him his name and Conan improvises the name of "Arthur Hirai".

There, Conan must obey him if he wants to return to Japan he has his glasses, wristwatch and clothes confiscated, among other things, and must conceal his real identity.

However, Kaitō Kid wants to use him to get the sapphire and kidnaps him to take him to the city-state. Conan is stuck in Japan as he does not possess a passport. Still in Singapore, Makoto was in the midst of participating in a martial arts tournament where he is joined by Ran and Sonoko to encourage him. A local millionaire plots to recover it, and when it reappears at a Singaporean hotel exhibit, a murder takes place and a calling card of Kaitō Kid is found at the scene. The world's largest blue sapphire, the 'Blue Sapphire Fist', is said to have sunk when a pirate ship sank in the late 19th century off the coast of Singapore. The setting of the film takes place in Singapore, most notably surrounding the Marina Bay Sands. This was the last Heisei-era Case Closed film, released weeks before the 2019 Japanese imperial transition. It is the twenty-third installment of the Case Closed film series based on the manga series of the same name by Gosho Aoyama, following the 2018 film Case Closed: Zero the Enforcer. Case Closed: The Fist of Blue Sapphire, known as Detective Conan: The Fist of Blue Sapphire ( 名探偵コナン 紺青の 拳 ( フィスト ), Meitantei Konan: Konjō no Fisuto) in Japan, is a 2019 Japanese animated mystery film.
