Answer:
stereotyping.
Explanation:
Stereotyping: This is a phenomenon, in which a person's feelings towards the other person can be biased by keeping indifferent views. Usually, being biased towards a person, group, or thing demonstrate the favor and against views a person holds.
Stereotyping people holds prejudice because they believe that whatever a person's outside behavior reflects, the inner side of the person too.
A stereotype person holds behaviors that are often mistaken, or false for the other gender, race, etc. and these false beliefs may or may not reflect reality.
So, Hiroko's teacher carries stereotype behavior towards the Asian students.