Tengoku ni ichiban chikai shima

Mari Katsuragi (Tomoyo Harada) is a high school student in downtown Tokyo. She tells her mother that she wants to go visit New Caledonia to fulfill a promise with her late father who told her about the island closest to heaven, that one day they will go there together. She embarks on a group tour to New Caledonia where she meets Yuuichi Fukaya an older man who is somewhat of a playboy. Mari tells Yuuichi that she's searching for the island closest to heaven her father told her about. Yuuichi takes her around the island but Mari isn't convinced that this is the place her father mentioned. But through various adventures and being met with local people's warmth she discovers where the real island closest to heaven resides.