After Han Seoul-Oh tells Dominic Toretto that cops raided their garage in Baracoa, Dom realizes the heat is too much and disbands their crew, telling Han that it's time for him to go do his own thing. Han then tells him that he heard they're doing some crazy shit in Tokyo, and that he'll most likely go there.
When Han and Gisele Yashar become romantically involved following the theft of Hernan Reyes' multi million dollar vault in Rio de Janeiro, the two contemplated where they would go next. Gisele brings up Han's previous suggestion, Tokyo, as a possibility. Han, however, decides that they would get there "eventually".
Some time after, Han and Gisele, who have been traveling the world together, make it to Hong Kong. Living relatively well among the populace, Han begins to discuss settling down having a future together with her.. Gisele, however, believes that they are settling down, but appears to ignore the subtext of his words.
When Gisele loses her life during the fight against Owen Shaw and his group of thugs, a mourning Han decides to go to Tokyo, telling Tej Parker and Roman Pearce that "it's just something [he has] to do". 
Sean Boswell was sent to Tokyo as an alternative to going to prison. While there, he inadvertently angers the city's "Drift King", Takashi, when he speaks to his girlfriend, Neela. When he challenges him to a race, Han, who is a part of Takashi's group, gives him the keys to his Nissan Silvia S15 to race against him. After learning the hard way what drifting was, Sean is placed under Han's debt to do whatever Han asks. However, Han and Sean form a friendship with one another, and Han decides to help Sean master the art of drifting.
During a late night conversation, Han laments that Tokyo was his border town escape, similar to the ones in old western films, when cowboys would flee to Mexico. When Takashi learns that Han has been stealing money from his Yazuka-affiliated uncle, Kamata, he tries to kill him. During Han's bid for escape, his car is t-boned by Deckard Shaw, the brother of Owen Shaw, who claims responsibility as revenge and contacts Dominic Toretto as Han's car explodes.
Sean decides to talk to Kamata, Takashi's uncle, where he proposes a race, in which the loser will leave Tokyo and thus make peace once again. Kamata agrees, and Sean, along with his friends, rebuild his Dad's salvaged Mustang using the engine from Han's destroyed Nissan Silvia. Sean races Takashi and wins and Takashi leaves Tokyo. That night, while celebrating at a car meet. Twinkie informs Sean that a racer who has beaten people around Asia (although later removed in Furious 7 to fit the storyline) wants to race him. Sean agrees, and meets Dominic Toretto who is driving a Plymouth Road Runner that he won from Han and tells him that Han was his family. Dom and Sean begin their race which isn't shown but is later confirmed that Dom won.
Deckard Shaw's actions force Dominic to visit Tokyo in order to bring Han's remains back home to the United States. While he is there he meets with Sean Boswell and races him in which he wins. The two discuss Han and Sean returns what he could salvage from the RX-7's wreckage- a photo of Gisele and Dominic's cross necklace. When Sean asks what Dom would do to Han's killer, he tells him that "words haven't been invented yet". Dom then leaves Tokyo with Han's body, presumably keeping in touch with Sean.