Hi, I'm a US citizen, my nephew is a Filipino, we will go to Hong Kong for 3 days, what are requirements?

Hi, I'm a US citizen who is planning to go to HongKong for about 3 days, but I will be meeting my nephew ( who is a Filipino citizen with a passport and is 22 yrs old) in Manila. From Manila we intend to travel together to HongKong. Would there be any other requirements for either one of us besides our passports? and since he will be with me, does he require financial proof that will cover his expenses in HongKong? Thank you for your reply.