A bombing case at Nichiuri TV in autumn. The Satsuki Cup, which crowns the winner of Japan's Hyakunin Isshu, is currently being filmed inside the facility. The incident results in a big commotion and, while the building is burning to ashes, the only people left inside are Heiji and Kazuha. They get rescued just in time by Conan, who rushes to the scene. Both the identity and purposes of the bomber are unknown.

While confusion takes over due to the explosion, Conan meets a mysterious beautiful girl who claims she is "Heiji's fiancée". Her name is Momiji Ooka and she is the Kyoto High School champion of the Karuta game. As fate would have it, Kazuha is going to face Momiji in the Hyakunin Isshu, so she begins to train with the help of Heiji's mother, Shizuka, who is a skilled Karuta player.

At the same time, in a Japanese house in Arashiyama, Kyoto's outskirts, the reigning Satsuki Cup champion is murdered. Pictures of the crime scene reveal Momji's presence. Additionally, several Karuta cards were spread around the victim.

Conan and Heiji, along with the Osaka and Kyoto police departments, begin their investigation on the Satsuki Cup and the related murder case. As the inquiry goes on, they come across a secret connected with the Hyakunin Isshu. 

(Source: Detective Conan Wiki)

The story is set in the game's fictional southern Hinomoto city of Ohitoyoshi after it was successfully revitalized thanks to Hachiroku's tourism promotion. The city is now planning to host the first Maitetsu Festival to bring together Railords and their respective masters from all of Hinomoto. Inspired by the humans planning for the festival, the famed Suzushiro and other Railords are also hosting a "Railord Summit" at the railroad station cafe Amairo to share their collective wisdom.

Two years before the start of the series, Roberto "Coach B" Sebastián, Sr.'s son, Roberto "Basti" Sebastián, Jr., was killed by a gunman from a large syndicate which brought down the Barangay 143's Powerhouse team and led to today's events. Bren Park, a player for a Korean basketball team, had lost recently his family in a tragic accident during a snowstorm in South Korea that led him to quit basketball. However, following a revelation that he was his mother's child to a Filipino man, Bren went to Manila to search for him. Along the way, he joined a local basketball team, the Puzakals of Barangay 143.

Young flower enthusiast Tsubomi Hanasaki is often modest and quiet. But with her family moving to a new town, she aims to reinvent her image at her new school as someone more confident and outgoing. On moving day, she dreams of a mysterious tree in the sky guarded by a warrior named "Cure Moonlight." Tsubomi quickly learns that this was no ordinary dream when she encounters two mysterious fairies—Chypre and Coffret—who are being hunted down by a strange woman. When the woman summons a giant monster to attack the city, Tsubomi finds herself transforming into a warrior to fight the enemy! Taking on the alias "Cure Blossom," Tsubomi learns that the woman is part of a villainous group that aims to turn the world into a lifeless desert, with her new duty being to stop it from happening. As Tsubomi continues to battle more monsters and uncover the secrets behind Cure Moonlight, will she find the confidence needed to overcome her timid nature? [Written by MAL Rewrite]