Proof of onward travel to be shown to immigration officials.

I will be arriving at HK from India, along with my family for a holiday and desire to stay there for five days. Then I have planned to take the Star Ferry and visit Macau, stay there for two days and take the outbound flight from Macau to Kuala Lumpur, for which I have flight Tickets. Would that be a sufficient proof of having onward travel arrangements of ourselves, which can be shown to immigration officials to their satisfaction, while arriving at HK? I do not have the Star ferry ticket for travel from HK to Macau, which I plan to buy only after arriving at HK. Please advise.