TANTEI OPERA MILKY HOLMES MOVIE: GYAKUSHUU NO MILKY HOLMES

The film will feature a three-way battle between The Gentlemen Thief Empire, the Genius 4, and the Milky Holmes groups. Just as the Milky Holmes group is settling down to relax at a hot spring after their study tour, an alarm goes off, because The Gentlemen Thief Empire intend to steal a treasure. The two groups start to battle for who gets to use the "Toys," when suddenly the Genius 4 rush to the scene. (Source: Anime News Network) — Description from AniList community (anilist.co).