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So basically the couple endgame is blonde (long ish) hair ML and the MC is short dark haired. The MC is sexual partners (not fully consenting) with a gangster person who raised him I think(?).

It took place in China I believe. The ML and MC at end escape the city and they promise to find each other in the America, then they both passed from cancer or something like natural causes. ML and MC did find each other and live in the americas until MC passed from cancer, and ML went back to China and died there.