Osamu Hayashi (林修) is a Japanese (National Language) teacher at Toshin High School which is not a high school but a cram school for university entrance exams.
He is the most famous teacher in Japan at the moment. He is famous for his phrase "Itsuyaruka?---Imadesyo! (When will you do? --- Right now!)."
His phrase became known among Japanese people after he acted in TV commercial of Toshin High School in 2011.
He is one of the most talked-about people in Japan now, because he also acts in Toyota Motor's TV commercial, which imitates Toshin's TV commercial. In Toyota's TV commercial, he says "Itsukauka?---Imadesyo! (When will you buy? --- Right now!)"
Here is Osamu Hayashi in TV commercial of Toyota Motor Corporation.
Here is TV commercial of Toshin High School.
Toshin High School
Toyota Motor Corporation