At the age of six, Lan Xin arrived at an unfamiliar city. In this city, there was no winter season, and no snow, but she was still very happy because there was something more beautiful than snow here; it was the person who she’d secretly called her ‘Sister’.

She went to the same cram school as her sister, so now they were studying in the same class. However, she could only look at her sister from the sidelines, because her mother had told her that she couldn’t get close ...