Sakamoto Shunpei is a Japanese boy who moves to the United States with his father and older brother and settles in a place called Hope Town. Adjusting to his new home is hard at first, but he soon makes friends among the local children. Together they build a raft and set off down the Mississippi River. The single-episode 1998 OVA adapts a children's fantasy novel by Daisaku Ikeda and mixes adventure, drama and supernatural elements.