Other than English, foreign languages like Japanese and Korean were not taught in schools—unless one studied at a Foreign Languages High School. There were a few teachers who knew other foreign languages and taught during certain elective classes but the students could not have possibly learned the language within a week of the elective lessons.
Yun Jian was from Longmen Yi Junior High School. The school did not have any teachers who knew other foreign languages aside from English.
As for Ji Xuetang, she was consistently practicing with her tuition teachers even during weekends. That was how she learned three foreign languages.
When Ji Xuetang talked to Yun Jian in Japanese, it was assumed that Yun Jian could not have possibly understood it. At least, everyone watching had already thought that it would definitely end with Yun Jian losing.
It came as a surprise that Yun Jian knew Japanese—she knew Japanese too!
