When a cake from the cupboard disappears and her mother immediately accuses her, Maruko gets indignant and vows to find the real culprit. Discovering a set of dentures, she becomes convinced she’s solved the mystery and begins grilling Grandpa. At school too, she starts locating missing indoor shoes and pencil cases one after another, and soon she’s feeling every bit the master detective.
戸棚の中にあったケーキが無くなって、お母さんに犯人扱いされたまる子は、怒って真犯人を見つけ出すことに。入れ歯を見つけ、犯人を確信したまる子は、おじいちゃんを問いつめる。学校でも無くなった上履き、筆箱などを次々見つけ出すまる子は、すっかり名探偵気分。
