The power of children's wishes to come true in ways they never imagined is the impelling idea behind the masterful new film by Japanese maestro Koreeda.
In a handful of features since 1995's Maborosi, the now 50-year-old writer and director has created a distinctive body of work - social realist dramas whose stylistic composure and meditative pace brings small-scale human worlds into sharp focus - which entitles him to be mentioned in the same breath as his great countryman, Yasujiro Ozu.
Like the sublime Still Walking, his last film seen here, I Wish revisits his characteristic thematic preoccupation with family dynamics. Two brothers, separated by their parents' divorce, live at opposite ends of the island of Kyushu and wish - as such children always do - that their parents would reunite.
Koichi (Koki Maeda), the serious-minded 12-year-old, is with his mum and grandparents in coastal Kagoshima - in the shadow of a rumbling active volcano that becomes a minor character, though never a heavy-handed symbol; the eternally cheerful Ryu (Koki's real-life brother, Ohshiro) lives with his shiftless musician dad in urban Fukuoka.
When a new bullet train line is opened between the two cities, Koichi hears that there will be magic (the film's Japanese title means "miracle") in the moment that the first two trains pass each other. A mission is born. Before long, the two brothers' best mates sign up and the pint-sized plan unfolds.