GAJK-039 — A schoolgirl is tied up and trained in a storehouse. A naive girl who apprenticed to her grandfather's restaurant to take over the business. She falls into perverse hobbies disguised as training... Natsume Usui

Natsume, the granddaughter, is shocked to hear that her grandfather is closing the Western-style restaurant he has run for many years. Hearing that he has no successor due to his age, she offers to take over the business and asks him to train her. From then on, she spends almost every day after school at her grandfather's house, learning to cook. Her grandfather watches as his granddaughter gradually improves. However, one day, after seeing her in the bath with her uniform stained, he begins to harbor impure thoughts…