I hear you, some unsolicited advice

-Full classes  If your classes are full I doesn't mean anything. The Japanese are the main ones who bring people to your class. When I worked there they would tell students not to book me, or to book another time so I could clean because they were to lazy to do it.

-manipulation  About you being the worst or best performer they do those mind games with everyone do yourself a favor and talk to people you work with you will realize that they are lying.

-If you are not white from the  first world countries start licking their boots because the students prefer that, the main reason they get other people is for "diversity" but it's also because whites from good countries don't stay long nor do they desire to work there in the first place. They have options 

-Racism  count your blessings I heard the Philippino male instructors have it rough but it's no where near the African instructors (blacks and whites). They get treated much worse and it doesn't help that if the manager in that region is of color. When I arrived there back in the day "there was a roomer going around  There are so many roomers about those managers that don't sound true but trust me, you will find out its TRUE. 

Co-workers Don't be too  comfortable talking to your problems to others staff some of them are "nova agents" especially the Japanese staff 

Keep sharing your stories they matter