Meitantei Conan: Hanamaru na Answer

Jewelry stores across town are being robbed, but despite the crimes taking place, Conan's friend Ayumi is excited. She notices the burglaries bear a striking resemblance to the events of her favorite anime, Precure, and she's hopeful that she'll get to meet the "PreCures!" if the thieves show up again.

Conan and the Junior Detective League get assigned to guard Kaneko Jewelry Store, which is rumoured to be their next target. After tailing a suspicious customer and discovering the date of the crime, as well as their hideout, the police seem to round up the thieves - but Ayumi notices something odd... Can the Detective League solve the mystery with a cute twist?!

(Source: Official website, translated, edited)

Note: Special commemorative crossover episode between Detective Conan and Star Detective Precure! for the 30th anniversary of the Detective Conan series. This is one of two episodes, the other aired as episode 18 of Star Detective Precure! series.