Melbourne to Beijing via Hong Kong then cruise to Okinawa

Dear kind souls, I hold an Australian passport and will be flying from Melbourne to BJ. This is not a direct flight but with a connecting flight in Hong Kong. After two days in BJ, I will take a cruise from Tianjin Cruise Port and the first stop is Okinawa, Japan then to Hong Kong. If someone could just offer me a confirmation that I would be able to apply for the transit, I would really appreciate. IT is REALLy scary to be in communist country without a valid visa if I thought I am eligible and have somehow misunderstood. Thank you so much.