Liang Xia and Mao Liang have been together for nearly a decade, living in Beijing for the past five years. Liang Xia, a gifted painter who gave up a bright career to become the ideal girlfriend, waits for a proposal that never comes as Mao prioritizes his design-work over their relationship. One morning, while gloomily flipping through the morning news, Liang encounters a flashy infomercial for “magic” chocolates said to restore youthful energy, and she impulsively orders a box.
Her best friend, Bai Xiaoning, becomes a co-conspirator in a plan to publicly force a marriage proposal at Bai’s wedding. But the scheme backfires. Mao reacts with threats to end things, leaving Liang devastated. In a moment of heartbreak, Liang swallows one of the chocolates and suddenly wakes up in a new, unfamiliar body—she is the 17-year-old version of herself, yet she finds herself 11 years in the future. The reunion with her younger self, whom Bai befriends with a mix of awe and support, begins a series of astonishing shifts: the 17-year-old “Little Liang” parties with Bai, while the older “Big Liang” tries to make sense of her grown life.
The mystery deepens when a fateful car crash seems to have triggered the change. Liang and Bai attempt to exploit the accident by bribing a taxi driver to speed up and slow down, only to be detained by the police. While Liang waits to be picked up by Mao, she comforts herself with another bite of chocolate and is transformed again—this time back into Little Liang. In the subway, the young version of Liang encounters a striking young man named Yan Yan, sketching a portrait of him before the spell wears off and she reverts to her 28-year-old self, leaving Yan with a drawing in his hands.
Mao is lambasted by his boss, Mr. Gao, who presents a top trending Weibo post of the subway-sketch and Little Liang’s image, praising Liang’s talent and proposing that she join their design team. Mao is stunned to learn that Liang has resumed her artistic spark, reopening doors that had seemed closed for years. The chocolate mechanism—each time Big Liang eats one, Little Liang takes over for five hours—becomes a revealing lens for their lives. The two Liangs begin communicating through video messages and voice notes stored in their devices, yet their priorities clash more than they align. Big Liang wants to prove her worth to Mao and to the agency, while Little Liang’s heart yearns for the romance she once imagined as real, especially as she becomes enmeshed in a flirtatious, carefree connection with Yan Yan.
Big Liang’s artistic confidence falters after years away from her craft, so she reluctantly summons Little Liang to help with designs for Mao’s agency. Little Liang, free-spirited and curious, dives into a new social world with Yan Yan and his biker friends, even as she tries to fulfill a deeper longing for intimacy. A camping trip turns tense when Yan kisses her neck; Little Liang, who is a virgin, hesitates and turns to Big Liang for a more experienced touch, recording a voice message asking Big Liang to reciprocate on her behalf. When Big Liang agrees, she pulls away in shock and eventually uses a bold kiss to reveal her renewed feelings in front of Yan’s world.
A turning point arrives when Big Liang lands a major contract using Little Liang’s sketches, and Mao seems impressed by the return of Liang’s artistic fire. Yet the moment of triumph is tempered by a painful revelation: Mao confesses to Xiao Yu that he doubts the couple will stay together in the long term. Overhearing this, Big Liang sinks into despair and retreats home, where she consumes another chocolate. The two Liangs decide to push their collaboration further, and their shared creativity fills a room with art, bringing a fragile, joyous relief to both of them.
In the wake of the gallery’s public success, Big Liang and Bai realize their remaining time is limited—the factory that produced the magic chocolates was destroyed in a meteor accident, leaving them with just a handful of doses. Grateful to her younger self for pushing her beyond fear, Big Liang records a farewell message to Little Liang and consumes the last chocolate that can sustain their presence for a while longer. Little Liang, meanwhile, discovers that Yan has a new girlfriend and that her sporadic appearances and disappearances have left him wary. A tense confrontation in a biker bar ends with Yan and his girlfriend preparing to leave the city, and Little Liang’s final attempt to win him back ends in disappointment.
Desperation drives Little Liang to take nine remaining chocolates at once in a bid to stay longer. She reaches a train platform, but her vision blurs and she collapses. She is rushed to a hospital where Liang’s life hangs in the balance. Inside Liang’s psyche, the two halves meet for the first time, and Little Liang breaks down, confessing that no one in Big Liang’s world cares for her. Big Liang consoles her younger self, assuring her that she has left a lasting, positive imprint on Liang’s life. The mental storm subsides as Little Liang’s spirit accepts that her vitality will endure within Liang, and with a last breath of pride she vanishes, freeing Liang to return to the living world.
Time passes, and in a new city a digital billboard bearing one of Liang’s designs glows for all to see. Back in Beijing, Mao races naked through the streets—desperate and hopeful—carrying a makeshift sign asking Liang to take him back. Liang, gazing down from her window, offers a quiet, ambiguous smile. The ending keeps the door open for reconciliation, balancing the ache of what was with the possibility of what could be, and leaving the audience with a lingering sense that art, memory, and love can shift through time in unexpected ways.
