Cheng Xiaoshi is depicted as a tall, slender young man with fair skin, light brown eyes, and sharp facial features. He has curly black hair that parts slightly above his left eye and falls a few inches past the nape of his neck.

In Season 1, his primary outfit consists of a steel-blue and cream-colored letterman jacket featuring mirrored orange hawk emblems on the chest, worn over a plain white T-shirt. He pairs this with black pants, black socks, and grey slip-on shoes.

In Season 2, his attire changes to a black letterman jacket with a clock symbol on the chest, layered over a white hoodie. He wears black pants with thin white stripes along the sides and white shoes. Alternative designs, released on his official character page by Bilibili and illustrated by INPLICK, depict him in a black and white version of his jacket with white hawks, a black shirt, and black shoes.

Flashbacks show variations of his wardrobe during different life stages. As a high school student, he is seen wearing what appears to be the school uniform: a grey dress shirt with the collar open beneath a blazer. At university, he wears a loose, steel-blue and grey striped shirt with wide shoulders, a small brown belt, black knee-length shorts, black socks, and grey slip-ons. During his graduation, he dons the standard charcoal-black gown with a teal and white stole, a teal emblem on the chest, and a mortarboard with a teal underside and red tassel.

He is also shown in casual or situational clothing. For instance, while repainting the Time Photo Studio in Episode 10, he wears a black T-shirt, a grey-blue apron, cuffed blue jeans, black sandals, and a white mask over his face.

When using his ability to enter photographs and inhabit another person’s body, his physical appearance changes to match the individual, though his eyes take on a distinct golden hue.

Cheng Xiaoshi is characterized by his playful and carefree nature, often approaching life with childlike humor and mischief. He enjoys teasing others and joking around, though his brash and impulsive behavior frequently earns reprimands from Qiao Ling, who regards him as less dependable than Lu Guang. Even Lu Guang is occasionally exasperated by his antics, though he admits he was initially drawn to Cheng Xiaoshi’s naivety and sincerity when they first met.

Headstrong and emotionally driven, Cheng Xiaoshi tends to act on impulse, prioritizing instinct and empathy over careful judgment. This habit often places him at odds with Lu Guang’s cautious guidance, such as when he spoke to Emma’s mother while inhabiting her body against instructions, refused to accept defeat in Chen Xiao’s basketball game, or recklessly pursued a suspect while inhabiting Xu Shanshan. Although he gradually learns to temper his behavior after realizing the past cannot always be altered, he continues to challenge this principle, most notably when he resists a preordained course of action in an attempt to protect Lu Guang from capture.

Despite his impulsiveness, Cheng Xiaoshi is not without cunning. He has demonstrated keen intelligence and adaptability under pressure, devising strategies to outwit adversaries such as his plan to expose Liu Min, and later using his abilities resourcefully to evade Li Tianchen while tricking him into freeing Lu Guang. His quick thinking and resilience in high-stress situations reveal a sharper mind than his easygoing persona suggests.

Underlying his recklessness is a deep compassion and strong moral conviction. Highly empathetic, he is driven by a desire to do what he believes is right, even at great personal cost. This is exemplified by his attempts to save future earthquake victims despite knowing it would irreversibly alter the timeline, and his willingness to shield Qiao Ling and Li Tianxi from gunfire at the risk of his own life. Although he often acts without considering long-term consequences, he is heavily affected by the outcomes, blaming himself for tragedies such as Emma’s death and Xu Shanshan’s disappearance.

Cheng Xiaoshi also carries personal scars from his past, particularly the abandonment of his parents during childhood. Sensitive to this subject, he would lash out when others assumed they were dead, and he continues to hold onto hope that they may still be alive. This lingering pain fuels both his optimism and his inner struggles, shaping his need for connection and his tendency to act with his heart.

Time Jumper
Cheng Xiaoshi possesses the ability to project his consciousness into the body of the person who took a photograph, effectively inhabiting them at the moment the picture was captured. Initially, this power is activated through a high-five with Lu Guang or by high-fiving himself, though he later discovers he can trigger the ability independently by physically touching the photograph. While in another body, Cheng Xiaoshi retains and transfers his own physical capabilities, allowing him to override the host’s limitations. Examples include striking with his own strength while inhabiting Dou Dou’s body, or seeing clearly without glasses when inside Chen Xiao’s body.

Shared Consciousness
When connected with Lu Guang, Cheng Xiaoshi can share his consciousness with him, enabling direct communication. This link allows Lu Guang to guide Cheng Xiaoshi’s actions from the outside, coordinating their efforts to fulfill the client’s request and maintain control over the altered timeline.

Lu Guang
Cheng Xiaoshi first met Lu Guang during their university years, when he invited him to join a basketball game with mutual friends. The two quickly developed mutual respect, with Cheng Xiaoshi feeling he could trust Lu Guang, while Lu Guang was drawn to Cheng Xiaoshi’s sincerity. Inspired by this, Cheng Xiaoshi suggested that they should become partners in the future, a promise that eventually materialized when they later opened the Time Photo Studio together.

During university, they were part of a close friend group that included Qiao Ling, Xu Shanshan, and Dong Yi. Their friendship deepened after graduation as they became business partners, combining Cheng Xiaoshi’s ability to enter photographs with Lu Guang’s guidance and foresight to fulfill clients’ requests.

Qiao Ling
Qiao Ling is one of Cheng Xiaoshi’s earliest and most enduring friends, often described as having a sibling-like bond with him. She has remained by his side throughout his life, acting as a protective older sister figure. Though frequently exasperated by Cheng Xiaoshi’s immaturity, she recognizes his strengths and struggles, offering him steady support. Cheng Xiaoshi, in turn, is deeply appreciative of her loyalty and care, openly thanking her for her presence in his life.

Their relationship is marked by mutual protectiveness, with both stepping in to defend one another when threatened. Examples include their confrontation with Ma and Qiao Ling’s slap against Qian Jin, as well as Cheng Xiaoshi’s willingness to shield her from gunfire, putting his life at risk to protect her.

Emma
Among the clients featured in the series, Emma leaves the greatest emotional impact on Cheng Xiaoshi. Witnessing the hardships and injustices in her life resonates strongly with him, particularly her yearning for a simple life with her parents. Having endured the absence of his own parents for over a decade, Cheng Xiaoshi sympathizes deeply and projects his own feelings onto her. This empathy ultimately drives him to interfere, sending a heartfelt message to Emma’s parents on her behalf, a decision that inadvertently leads to her tragic fate.

Xu Shanshan
Xu Shanshan, another university friend, shares a more combative but lighthearted dynamic with Cheng Xiaoshi. Their interactions are often filled with playful bickering and sharp remarks, though they harbor no true hostility and remain comfortable within the same social circle. Cheng Xiaoshi shows genuine concern for her well-being, particularly after she becomes one of Liu Min’s victims.

Shanshan first visits the Time Photo Studio after missing a crucial moment during her graduation party due to drinking too much. Although initially skeptical of Cheng Xiaoshi’s professionalism, she ultimately entrusts him with the task after reassurance from Qiao Ling.

Cheng Xiaoshi’s surname Cheng (程) is a common Chinese family name. His given name, Xiaoshi (小时), literally means “hour.” In the context of naming, 程 (Cheng) can also carry the meaning of “journey” (as in 路程, lùchéng), giving his full name a possible interpretation of “journey through the hours,” a likely reference to his time-related ability.

Additionally, the final character of his given name, 时 (shí, “time” or “hour”), combines with Lu Guang’s given name, 光 (guāng, “light” or “brilliance”), to form the word 时光 (shíguāng), which means “time” in the sense of its continuous flow. This word also appears in the Chinese title of the series.

In promotional material released prior to the premiere of Season 1, Cheng Xiaoshi’s official English name was listed as “Charles,” a French name meaning “free man.”