What is the right time to send my kids to pre-school?

The right time to send your kids to preschool is 1.5 yrs, in the playgroup class where they will learn to settle in a new environment and recognize their environment, teachers and friends. If your are not comfortable sending them at 1.5 yrs, then you can skip a year and make them join at 2.5 yrs in Nursery class, because by this time, kids start to grasp information from their surroundings in a fast manner and its always better if they get a right direction to early childhood learning in a pre-school, rather than being at home. To have more idea about prechool structure and age criteria you can visit the following site Kidzee Goregaon Preschool. 

While most preschools start the enrolment for the children in the age group from 3 years to 4 years old, there is no predefined best age as there are other factors apart from children's age that determines the appropriate age to start preschool for your kid. Global Indian International School is one of the best pre-school's in Tokyo, Japan which you can consider if you are looking for one.