Teacher need to realize students are an individual, each with their own complex emotion and personality. I know he means well, but failing to realize that the students are malicious towards another is your own failure as a teacher.
That said, I'm glad someone like Taiyo comes into her life. What she needs is not a "push" like the teacher does.
What she needs instead is a "pull". For someone to be beside her while she's breaking out of her comfort zone.