The place is a Japanese larch grove in the Eastern Hokkaido village of Tsurui, the time is just before dusk. A red-crowned crane flock hurries to their roost for the night.
March marks the beginning of the mating season for red-crowned cranes. It is also a season for parting with offspring born in the previous spring. Parents stop taking care of their young, and encourage them to become independent by pushing them away if the young approach. Young that had followed their parents around up through mid-February start to go off on their own more and more, and stop following their parents altogether when the snow melts.

Red-crowned cranes were plentiful throughout Hokkaido in the 1800s. But in the early 1900s, sighting reports died out and the cranes were thought to have gone extinct. After being rediscovered, conservation efforts bore fruit, and population numbers started increasing mainly in the Kushiro Marshland area. In the 2000s, young cranes seeking new breeding grounds on their own have started gradually expanding their habitat into Northern and Central Hokkaido.

After leaving their parents, mature red-crowned cranes join their mating partners to gradually repopulate areas that have not seen cranes in their skies for over a hundred years.