After his parents get divorced, Koichi winds up living with his mother and grandparents in Kagoshima, while his brother Ryunosuke lives with their father in Fukuoka. The brothers dream of their family being reunited one day, so they're both very excited when the Kyushu Shinkansen is completed, especially when they hear that a miracle will occur when the first trains meet. Because of this, they decide to do whatever they can do make sure this miracle actually takes place.