Bruce Lee, My Brother is a dramatic biopic of the eponymous martial arts legend as told by his younger brother, Robert Lee. Based directly from the book "Memories of Lee Siu Loong", which is authored by Lee's siblings (Phoebe, Robert, Agnes and Peter),[3][4] it revolves around Bruce Lee's life as a rebellious adolescent in Hong Kong before he sets off for the USA and conquers the world at the age of 18 with only US$102 in his pocket. As a young man, Bruce grew up in an affluent family. Entering the film industry at an early age, he gained fame as a child actor. Outside the home and studio, he was rebellious; he spent time engaging in street fights, dancing with lady friends, and hanging with his buddies, Kong and Unicorn, the latter a fellow child actor who would later appear in Fist of Fury and Way of the Dragon. Invincible as he is as a street fighter, Bruce's romantic escapades are not as smooth and successful. He is head-over-heels in love with Pearl, only to realize his mate Kong shares the same passion. At a cha-cha dancing tournament, Kong tells Bruce his intentions of leaving Pearl so Bruce himself can have her, damaging their friendship. Bruce is unable to come to terms with Kong. Against his father's wishes, Bruce studies the Wing Chun martial arts style instead of Tai-chi and tastes his first public triumph at a tournament with his kung fu skills. On the eve of his triumph, he learns that Kong has become a drug addict. The same boxer whom Bruce defeated at the ring informs him of his whereabouts. Bruce rumbles the drug lord's den together with Unicorn to rescue Kong, but the drug dealers confront them. Their actions cause a massive chase sequence; although Bruce and his friends survive, Kong would later die from his drug overdose. Bruce himself became the target of both the Triads and corrupted cops who want him in jail. To save his life, Bruce's father has no choice but to send him off to San Francisco, California.

There is Kung-fu tournament held once every 18 years. Yuen Nan Tin, a skilled fighter, attends the tournament with a boy, Siew Yee Yee, in order to prevent any unnecessary killings. But Yuen is badly injured at last and Siew Yee Yee is saved by the group of 10 mischievous people who intend to mould him into the fiercest person in the land. The princess of Yee Fah Kung, a skilled fighter too, has also adopted a small girl Fah Moh Kuit. She dresses the girl in boy's clothing and trains her to win the next tournament.