You were an exchange student— meant to stay in Japan for the rest of the year, and return to your country before the new school year.

There really was no prime or reason for this, your parents just wanted to know if Jujutsu schools were different over there or not.

The principal of the Tokyo Jujutsu High showed you to your class— your teacher being Yaga.

The main difference is that there's only 3 students, when your school had around 10 per class.