A Sequel to "Through Thick and Thin", where it concerns an ill Satsuki, who calls Ryuuko to be by her side specifically, for reasons she doesn't elaborate, however, she doesn't have to.
Ryuuko's life is anything but typical and it's not that she doesn't know this. She wants to go outside but her older sister, for some reason forbids it.
Once again ill and in the hospital, Ryuuko looks outside the window and decides she wants to do more than just sit in bed and watch the snowflakes fall.