It’s been 7 years since Yuuichi Aizawa visited his aunt Akiko, but now that his parents have gone to Africa to pursue their careers, he is finally back in the little northern town. Yuuichi is not really overjoyed with the prospect of living here though, because all of his memories of this place and the people living in it have mysteriously vanished. His cute cousin Nayuki seems like a stranger as well, even though he used to play with her all the time when they were younger.

On the day of moving into his new home, Yuuichi starts unpacking the boxes and stumbles upon a red headband that no one seems to recognize. This is one of the first clues that will make Yuuichi take a stroll through the snow-covered town and make him start recalling fragments of his past, broken promises and buried secrets. Yuuichi soon realizes that there is something supernatural going on, and all of his new female acquaintances seem to have links to his forgotten past.

The spring has come since Yuuichi reunited with Ayu, and lives of all major characters are back on track. When Mishio visits Makoto's birthplace, however, a miracle happens before her eyes.

[Source: Anime News Network]

"One snowy winter's day... I sit on a bench near the station, waiting to meet my cousin Minase Nayuki; it has been seven years since I last saw her. This place is far from the town where I was born and lived until yesterday. This is where Nayuki lives with her mother, who has offered to take me in, now that I am forced to move so suddenly. And this is the town in which my faintest, cloudiest childhood memories are set..." — Yuuichi

A young man, Aizawa Yuuichi, gets off a train and leaves the station as he enters a town that is blanketed by snow. He left the area seven years ago and has now returned to his memories that he left behind. Although his past is blurry in his mind, the girls that still remember him and that he had relationships with begin to help him remember. While this happens, the bad memories of his past also begin to come back, and will eventually haunt him.

[Source: AniDB]

――This is the story of a small miracle.
Stars from different universes and different times that were never meant to cross paths. By irony of fate, these stars come together in “Kaginado Academy”.
What awaits them there is a lively school life full of hope and dreams.
The wonderful encounters provide the stars with new radiance.
What awaits beyond that radiance...?

[Source: official website]