What type of visa do I need? How many Entries?

I will fly from Washington DC to BeiJing. Stay in BeiJing for 2 days then fly to Hong Kong. Then take a train to Guilin the next day for 5 days. Then I will return to Hong Kong via train and stay in Hong Kong for 3 days. Then I will fly from Hong Kong to Tokyo Japan with a layover in BeiJing inbetween. After 2 days, I would then fly from Tokyo to DC with another layover in Beijing. How many entries would this count as and, thus, what type of Visa would I need?