Below is a map of the monarchies of Asia. There are currently six countries who have a king:
Bhutan: Jigme Khesar Namgyel Wangchuk
Brunei: Sultan Hassanal Bolkiah
Cambodia: King Norodom Sihamoni
Japan: Emperor Naruhito
Malaysia: The Yang di-Pertuan Agong (a king elected for a five-year term.)
Thailand: King Maha Vajiralongkorn
The Kingdom of Nepal is defunct. King Birendra and Queen Aishwarya, along with several other members of the royal family, were gunned down on June 1, 2001 in an act of regicide. In 2008, Nepal was declared a republic.