"Do you know the world of Ssanahee Sunjung?" After leaving the city for Magari, Mr. Yoo, a poet stays at Won-bo's house, whose dream is to become a fairytale writer. From the first day he came, he said, "When I see Mr. Yoo, my heart grows". He said that he knew the world of innocence and that he knew the world of children. Won-bo's dream is to become a fairytale writer who inspires passion in children's hearts. Won-bo, who only talks about strange things, and Mr. Yoo, who live under the same roof, adjust to both of their lives, and regain their ' innocence and 'children's heart'!