Paranoia Agent (2004)

In Musashino, Tokyo, a young elementary school student is terrorizing the streets, attacking unsuspecting victims. Dubbed "Lil Slugger" by the media, his targets can’t remember what he looks like, but they all share a few vivid details: he wears shiny golden inline skates, a baseball cap, and wields a crooked golden baseball bat. Detectives Ikari and Maniwa take on the challenge of capturing this elusive child and stopping his reign of chaos.