What season is it when a girl with a big face goes to her grandmother's house in the country?

It happened in the anime 13 episode, and the eldest sister went to her grandmother's house in the country. In episode 13 of Shuai, Shuai's big-faced sister went to her grandmother's house in the country. This episode is about a "mouse holiday" at school, so Shuai took her to her grandmother's house in the country to play, and a series of funny stories happened in the country. A Shui and a Big Face Girl are two main characters in Chinese mainland's famous cartoon "A Shui", which was produced and distributed by CCTV animation.