My daughter intends to go to japan to attend a conference by 3rd week of August. she has already obtained visa for japan. According to flight schdule she will fly through Hong Kong by Cathay Pacific airline. In both ways she has abou 4 hours transit time at Hongkong Airport. She doen noe expect to leave the airport. Does she require transit visa for Hongkong?. If the answer is yes, it must be a double entry. Isn't it?

Appreciate your help.