Sekisou no Aestivum

One winter night, a young boy named Rishu wakes up in a forest.
Upon awakening, the first thing he sees are human footprints on the snow. Following the footprints, he comes across a young girl lying on the ground.

He woke the girl up, got to know her as Miharu Aika, and the two try to find a way out of the forest together.

A story of inexplicable mysteries and sad memories is being unfolded in a world of snow...