As a former employee of this school I can concur with all the other comments made about "Mr. Tan"! He is absolutely not to be trusted. Do not believe anything he tells you. In order to get you to work at the school he will promise you anything you ask for.... when you arrive you will find he is a liar, a cheat and all promises will be off! (Even if you have signed a contract!).
Deal with this man at your peril- if you do you will undoubtedly regret it!