Case Closed: The Crimson Love Letter is an anime film directed by Kobun Shizuno.

IN THE GAME OF DEATH...CONAN'S HOLDING ALL THE CARDS!

In Kyoto's picturesque old neighborhood of Higashiyama, murder is brewing. Detective Conan and friends are in town to support Ran's father, private investigator Kogoro Mori, as he interviews a well-connected businessman who runs a Karuta tournament. This means a rare visit with Conan and Ran's Osaka-based counterparts, teen detective Heiji Hattori and his friend Kazuha Toyama. But what's Karuta? Karuta is a unique blend of sports and classical literature, a game where players must listen carefully to Edo-era poems, then be the first to snatch the corresponding poem card off the playing field.

One aspiring Karuta champion is found dead in his home, his mysterious link to a missing master called into question. But before Conan and company can get their investigation going, would-be Karuta queen Momiji Ooka challenges Kazuha to a duel - a duel for the hand of the hapless Heiji Hattori!

The Crimson Love Letter is the twenty-first movie in the famous Detective Conan series, based on Gosho Aoyama's chronicles of a pint-sized detective solving giant-sized crimes. In this twisty mystery, Conan and Heiji, over the backdrop of old Kyoto's splendor, don't just have to make sure one truth prevails - they have to prove that two teen detectives really are better than one!