Asia Minor (Turkey) is at the extreme west of what is considered to be Asia proper. It has no connection with Southeast Asia whatsoever, which is made up of the countries of Vietnam, Laos, Cambodia,...
Many East Asian and Southeast Asian countries were once Buddhist empires. What is now China, Mongolia all the way south into Myanmar, Thailand and Indonesia were once Buddhist and Hindu empires....
There are more than seven countries of southeast Asia and east Asia. Here are seven countries Cambodia, Laos, Thailand, Indonesia, Singapore, Philippines, and Vietnam.