Shinobu Oomiya once departed Japan to take part in a homestay in England. While there, she formed a close friendship with Alice Cartelet, the daughter of the host family. However, when the time came for Shinobu to return to Japan, the two managed to convey their sadness despite the language barrier separating them. Five years later, now a first-year high school student, Shinobu receives an airmail letter written in a language she does not understand. The letter is from none other than Alice, describing her own homestay in Japan. In fact, Alice will be attending Shinobu's high school and living with her! Together with their friends Youko Inokuma, Aya Komichi, and Karen Kujou, the five girls attend school and learn about what their different cultures have to offer, day after day.