Singapore International School in Vietnam offers Chinese, and it has many campuses in many different cities.

If I relied on the teaching staff of a school as the basis for a social life, there would be nothing left for me but suicide.

That's why it's important to find a job is a festive city.

@Medillen

Generally even Low tier international school jobs are better than the best esl jobs. And there are plenty of Low tier schools in Vietnam struggling to fill math positions with licensed teachers. Many of these schools staff their math and science departments with teachers from the Philippines and India because licensed Teachers from U.S. And England are unavailable. Even with a middle school qualification many of these schools might hire you for a general secondary math position if you are youngish,not terrible looking, caucazoid, and interview well.

By the end of that year you will have a Licence and a year of experience as a math teacher at an "international school". Even a bad international school will count towards your steps on the salary scale of a future school. If you teach esl for a year, you will still be a math teacher with no experience.

The big emphasis on Halloween activities indicates, probably, that the student body is local and not expat. Schools that cater to local students are often the for profit "stinky" ones.

Parents of students at these schools like it that their children are going to an "international school" and celebrating a foreign holiday with a bunch of foreigners (ie. Teachers). Halloween is a famous foreign holiday and the foreign teachers are actually around for it (unlike Xmas when they go home). So a good Halloween celebration with not just witches and ghosts, but foreigners as well, is one of the perks of sending your kid to an international school instead of a good local private school.