The Mystery of the Stranger in the Checked Hat

My name is Ida Ha, and I love mysteries. I need to become a real detective to solve this complex case! Find the school thief, expose the bully in the local café, and figure out who poisoned the bun seller—all in one day! For Ida Ha, nothing is impossible! After all, she has the talent of a super detective! But with one mystery, she will have to puzzle over it: who is this suspicious stranger in the checked hat who keeps appearing in her path? And why did he appear at the moment when so many mysterious crimes began to occur around?