On the surface, Yim Ho seems poles apart from his subject. Yim is a filmmaker from a family of intellectuals, while the latter is a fisherman's son who outgrew his modest roots - he started education when he was 20 - to become a high-flying executive with the Swire Group. What brought the pair together was their common struggle to reconcile their doubts about British colonialism and the success they attained because of it - a central issue in Floating City, Yim's latest film based on a real-life rags-to-riches story. The film opens on the mainland today and will be released in Hong Kong on May 19. 'I think colonialism, by nature, is inhuman - illegal, even,' says Yim, who studied at the London Film School from 1973 to 1975 before returning to Hong Kong, when he would become part of the city's New Wave filmmaking movement. 'But historically, the colonialists have certainly made contributions here.' The protagonist in Floating City, Bo Wah-chuen (played by Aaron Kwok Fu-shing), is a beneficiary of the British regime, mirroring the Swire man's ascent of Hong Kong's social ladder - a story the retiree told Yim over dinner a few years ago. The young Bo began his climb out of poverty when he joined the fictional Imperial East India firm, where he advanced from errand boy to general manager under the mentorship of an expatriate chief executive. While his career thrives, Bo is constantly forced to contemplate his own identity: he has reinvented himself as a sophisticated, English-speaking executive, yet finds it difficult to mingle with the company's largely British elite and is forced to go through immigration checks in London as an alien because he doesn't have full-fledged British citizenship. Floating City presents British colonialism as having had a benign impact on Hong Kong - a view Yim would have rejected vehemently when he was younger. Yim's father, Yan Qingshu, was a veteran journalist at the pro-Beijing New Evening Post and a delegate to the Chinese People's Political Consultative Conference when he died, aged 62, in 1981. Yim studied at the leftist Heung To Middle School, and he admitted having 'actively participated' in the anti-government riots in 1967. Yim declined to elaborate on the reason for his change of heart, but says he is now patriotic in a different way. 'Back then I was much more sentimental and innocent,' he said. 'Now I regard it as a duty to love my country and to hope it will become better by the day.' Yim's best-known film, Homecoming, was seen as different from other movies released around the same time in 1984. While Yim's peers were making films about Hongkongers' anxiety and doubts about the impact of the Sino-British Joint Declaration, Homecoming presents a comparatively optimistic view of reconciliation between the then colony and the mainland as a Hong Kong office executive attempts to rekindle friendships in her hometown in eastern Guangdong. With Homecoming, Yim became the first Hong Kong filmmaker to make a full feature on the mainland after the end of isolationist policies in 1979. Yim would return to the mainland to make The Day the Sun Turned Cold in 1994, The Sun Has Ears in 1996, and his last film, A West Lake Moment, in 2004. The success of Echoes of the Rainbow in 2010 revived interest in films presenting a rose-tinted vision of Hong Kong's pre-handover years. It was around this time that Yim's screenplay for Floating City secured financial backing from Hong Kong-based Mandarin Films. 'What I wanted is to bring a feeling of those distant times [the late 20th century] to audiences, and let them make their own conclusions about the era,' he said. 'If you insist on deciphering these films, well, the media have to do this ... maybe it's just that society has become politicised, and we can't help it.'