Schoolgirl Tied Up and Trained in a Storehouse An innocent girl becomes an apprentice to inherit her grandfather's restaurant. She falls into a perverted hobby disguised as training... Natsume Usui
Hearing that her grandfather is closing the Western-style restaurant he has run for many years, his granddaughter Natsume is surprised. Learning that it's due to his age and lack of a successor, she offers, "I'll take over the restaurant, so please train me." From then on, after school each day, she begins learning cooking at her grandfather's house. Her grandfather watches his granddaughter improve. However, one day, he catches sight of her bathing after soiling her uniform, and a wicked feeling begins to stir within him.