Bon Bon forgets to study for her math test, so she cheats and gets away with it, but she gets disappointed from her lack of skill. She forgets to take the diary with her and Teddy takes it. Teddy comes up to Bon Bon and threatens to show off the diary if she doesn't come with him to the ball concert. Bon Bon calls Sweetheart to sort out the problem and she calls Teddy and tells him what keeping personal secrets is about. Teddy hands the diary to Ms. Hackney. Bon Bon confesses that she cheated to get an 'A' and Ms. Hackney gives her diary back. After taking a resit, Bon Bon gets a 'C', but Teddy flunks his test and Bon Bon offers to study with him so they can pass the next test before going to the ball concert. Episode Song: "Secrets", sung by the girls.