7 titles recommended if you like The First Slam Dunk
Rascal Does Not Dream of a Knapsack Kid
xxxHOLiC The Movie: A Midsummer Night's Dream
Bleach the Movie: Fade to Black
Sing a Bit of Harmony
Trinity Seven: Heaven's Library & Crimson Lord
One Piece "3D2Y": Overcome Ace's Death! Luffy's Vow to his Friends
Fate/Grand Order the Movie: Divine Realm of the Round Table: Camelot 1 Wandering; Agateram