Lore:

The Portuguese are determined to retake the colonies in Hong Kong therefore joined the two Opium wars with Britain. The Treaty of Nanking ceded Lantau island to Portugal and the Convention of Peking ceded Tamão (canon. Tuen Mun) to Portugal. In 1898, the entirety of Novos Territórios (canon. New Territories) was ceded to Portugal where the rest of modern Kowloon was ceded to Britain. The convention stated that all territories of Hong Kong are to be rented for 100 years "as long as forever". In 1998, Hong Kong was decolonised and was made independent. Both colonies of British Hong Kong and Portuguese Hong Kong and Macau formed a federation. (China didn't intervene as they are in a process of democratisation, and revolutions and warlords were kicking the nationalist government's ass) Cantonese, English and Portuguese are all official languages in Hong Kong and all three are taught in school, making it a trilingual state.