Met, a young man who died of heart failure on his 22nd birthday, becomes a ghost, unable to move on. With no family visiting his grave, he lives in solitude in the cemetery. One year during the Qingming Festival, a boy named Than visits the grave next to Met’s. Realizing Than can see ghosts, Met begins to look forward to his annual visits. But after Than’s father dies, he stops coming. Met is disheartened, but years later, Than—now a college student—reappears.

Than believes Met can't pass on because he doesn't know the true cause of his death. He invites Met to live in his room and helps him uncover the truth. Living with a ghost in secret is thrilling for Than, especially since his friends Prince, Kao, and Plai know nothing. Taking Met out is a challenge, but one day, Met follows Than to his university and remembers that he once studied there himself.

Than scores high on an exam with Met's help, raising suspicions in Prince and Kao. While searching for clues in the library, they learn that a thesis Met wrote is kept in a locked archive. Than lies to Prince and Kao, telling them the archive holds past exam papers, and plans a midnight break-in to retrieve the thesis.

Than tries to get a list of heart disease patients from the year Met died through Kao’s sister, who works at a hospital. Secretly in love with Than, Plai asks Prince for birthday gift advice. Meanwhile, Prince and Kao suspect Than’s odd behavior might be due to drugs. Depressed after being mocked as gay by his basketball teammates, Than confides in Met about the worries he’s long kept hidden.

Than finally discovers Met’s full name and address and takes him to his old house. But upon seeing the house, Met begins to vanish. Prince, Kao, and Plai throw a costume party at a bar to celebrate Than’s birthday. Drunk, Plai kisses Than when he takes her home. From that night on, Met disappears. Desperate to explain the misunderstanding, Than collapses in the rain.

Than confesses his feelings to Met after he returns, but Met vanishes again. Instead, Than’s mother, Kwan, appears in his room. Concerned, Prince and Kao ask Plai for help, but Than remains closed off. Frustrated by his ambiguity, Prince confronts him. Unable to hide anymore, Than finally comes out as gay to his friends and mother.

Than learns that his mother Kwan was Met’s ex-girlfriend and takes her to the cemetery. Reuniting with Met, Than reveals he has found Met’s real home. It turns out Met was related to Plai. At Plai’s house, Than finds a hidden photo of Met and learns about a sealed room. With Prince and Kao’s help, he sneaks in with Met.

In the sealed room, Met remembers seeing Plai’s grandfather, Pop, at the moment of his death. Than suspects Pop let Met die and confronts him. Pop eventually explains the circumstances that led to Met’s death. Plai, learning the truth, offers to perform a memorial rite to help Met pass on. But for Than, that would mean saying goodbye to Met forever.