Siao San, Steven Hao Shao Wen, is a mischievous little boy from a well‑off family who feels neglected by his father after the man marries a younger woman. After a punishment for playing a trick on his new step‑grandmother, San decides to run away from home. Tat, Richard Ng Man-Tat, is a middle‑aged school groundskeeper who harbors a quiet crush on a blind floral girl, a crush he indulges by pretending to be a wealthy man who buys her flowers only to gift them back. Their paths collide when, in a park, a woman chasing San for stealing candy from a baby strikes Tat with a bat. In a moment of reckless retaliation, Tat uses the bat and hits a police officer, forcing both men to flee and forcing them to rely on each other to escape capture.
San resolves to follow Tat, and despite Tat’s attempts to rid himself of the boy, San dogs his steps all the way to Tat’s home and even to the high school where Tat eventually works. At the school, Mo, Takeshi Kaneshiro, is the popular student who longs for the attention of Ah Jane, but his schemes to win her over are continually thwarted. Mo’s charisma shines even as the class itself—class 5D—narrows into a notorious group of misfits who pull dangerous pranks to unsettle their teachers. A new teacher arrives, only to be overwhelmed by the class’s antics and even collapse from the stress, carried out of the building in an ambulance. The downpour outside becomes a symbol of the chaos inside when San sits in the rain outside Tat’s door until Tat takes him in, offering temporary shelter and a sense of belonging.
The next day, Tat takes San into the city to perform odd jobs and even con others to earn money, with the aim of continuing to buy flowers for the blind girl. He learns that the operation to restore her sight would cost HKD 500,000, a sum she is tirelessly trying to raise through her flower trade. The school’s administration, meanwhile, faces a revolving door of teachers as eight have come and gone since the year began, prompting the blind and deaf headmaster to personally step in to teach class 5D. He administers a pop quiz with the threat of expulsion, triggering a wave of clever cheating by students trying to hide their lapses from him. When cheating proves insufficient, the school offers HKD 500,000 in salary to anyone capable of handling class 5D, a tempting—but daunting—challenge.
San pushes Tat to accept the job, but Tat remains hesitant because of the class’s infamous reputation. San proposes a shortcut: he’ll introduce Tat to someone who can teach him martial arts. A monk apprentice arrives to meet Tat, who initially mistakes him for a homeless man, only to be astonished when the monk’s powers truly appear, and the two end up training under a temple’s guidance. The Head monk eventually recognizes their potential and accepts them as apprentices, even if the training feels rough around the edges. Under the Head monk’s tutelage, Tat becomes a capable martial artist and, together with San, graduates from the early lessons in hypnotism, albeit in a manner that feels imperfect and improvised.
Tat then takes on as the instructor for class 5D, countering the pranks that had defined the previous tenure. The next days see him pushing the students through boot‑camp like drills, urging them to study harder and to retake the quizzes. He visits the blind girl, offering to pay for the surgery that could restore her sight, a gesture that deepens his commitment to helping others, even as the school’s politics threaten his position. Mo presses Tat to hypnotize him into reliving a past life, but Tat refuses to yield to such requests. The biker who hassled Jane again tests Mo, and when Tat steps in to break the fight, Mo’s status with the class rises—yet Tat pays a price, losing the teaching job and the promised bonus that could fund the blind girl’s operation.
Feeling the weight of his choices, San and Tat revisit San’s old home to retrieve money from his father’s safe. San is torn as he hands over the money to Tat, then watches Tat leave, choosing not to stay with San but to pursue a steadier path instead. After giving the funds to the flower seller, Tat returns home to confess his misdeeds to San’s father and pledges to repay what he’s taken. Though offered a chance to stay with San, Tat declines and instead takes on a series of honest, menial jobs. He eventually crosses paths with the blind girl again at her shop, though she doesn’t recognize him at first because he has remained silent. When he finally speaks, her recognition is a shock, but her husband’s approach compels him to walk away. In the end, Tat and San are reunited only after San runs away from home once more, continuing a loop of dependence, risk, and resilience that threads through the film’s emotional core.
Throughout, the film balances tender moments of care with the humor born of misfits and mistaken identities, weaving a story about responsibility, redemption, and the complicated ways families—and chosen families—come to terms with love, sacrifice, and the costs of trying to do right.
