Lu Guang/Relationships

== Time Photo Studio ==
=== Cheng Xiaoshi ===
As far as is currently known, Lu Guang first met Cheng Xiaoshi in high school. The two became acquainted when Cheng Xiaoshi asked Lu Guang to join him and a couple of others in a game of basketball. The two quickly took a liking to each other during the game, Lu Guang liking Cheng Xiaoshi's inherent naivety, and Cheng Xiaoshi feeling Lu Guang was someone he could count on. This directly led to Cheng Xiaoshi suggesting that they should became partners in the future. Lu Guang remained slightly skeptic, but did not outright disagree. It's implied that they became regular basketball buddies after this, whose relationship then gradually turned into a deeper and more serious friendship.
The two attended the same university, and hung out in the same social circles, mostly consisting of them, Qiao Ling, Xu Shanshan, and Dong Yi. After graduating, they went on to open up the Time Photo Studio together, thus indeed becoming partners as per Cheng Xiaoshi's early suggestion.
By the start of Link Click, Lu Guang and Cheng Xiaoshi have already long since become best friends, with all the familiarity and warmth of such a relationship present between them. They generally get along very well, but do at times quarrel upon sporting a difference of opinion. Mostly such scenarios tend to arise during their dives in time, when their somewhat conflicting morals clash or Cheng Xiaoshi gets swept into their client's emotions. However, they aren't keen on staying angry with each other, and tend to move past disagreements fairly swiftly. 
Lu Guang is shown to be highly attuned to Cheng Xiaoshi's emotional state, frequently offering him comfort or reassurances when he needs it. Being very aware of his partner's impulsiveness, Lu Guang also has a habit of keeping things secret from Cheng Xiaoshi, especially when he predicts it might elicit a strong emotional reaction from the other. Cheng Xiaoshi, for his part, is shown to occasionally go behind Lu Guang's back, too. Such actions are, nevertheless, clearly performed out of a desire to avoid conflict and/or the other getting hurt, rather than any real malice.
=== Qiao Ling ===
Lu Guang and Qiao Ling are first introduced by accident, with Lu Guang walking past the Time Photo Studio, and Qiao Ling noticing that he knows Cheng Xiaoshi. Curious, she invites him to help them in renovating the studio, which he accepts. After being left alone together for a moment, Qiao Ling questions Lu Guang’s reasons for being Cheng Xiaoshi’s friend. He answers by stating that he likes Cheng Xiaoshi’s genuineness and naivety. As she later admits to agreeing with this sentiment, it is presumably also what ultimately won Lu Guang her favor.
Lu Guang and Qiao Ling’s friendship is not as conspicuous as either one’s relationship with Cheng Xiaoshi, but there appears to be a level of familiar fondness between them. Qiao Ling sometimes even affectionately calls him "Guang Guang." as well as openly considers him to be the more reliable one. Lu Guang seems to possess a similar view of her, indicated when he privately instructs her to keep Cheng Xiaoshi from doing anything reckless while he goes to see Xiao Li. Just like with Cheng Xiaoshi, Lu Guang is similarly shown to watch out for Qiao Ling, too. Most prominent example of this would be him intervening when he assumed Chen Xiao was about to assault her on her morning run.
== Others ==
=== Xiao Li ===
Lu Guang and Captain Xiao Li briefly meet during the investigation of Dou Dou's kidnapping, as Xiao Li is accompanying Dou Dou's father when he comes to the Time Photo Studio in search of help. The two become properly acquainted in the aftermath of the case being solved, with Xiao Li revealing he is aware of Cheng Xiaoshi's time-traveling power and attempting to rope him into an ongoing serial murder investigation. Seeming reluctant to get involved from the start, Lu Guang then ultimately refuses on his partner's behalf after realising that Emma is one of the victims.
Later, when Xu Shanshan goes missing in ominous circumstances, Lu Guang, Cheng Xiaoshi, and Qiao Ling agree that help is needed from the police. Since Xiao Li is already in the know about their supernatural abilities, Lu Guang goes to him specifically. As it appears that the chief suspect of the serial murders is also responsible for Xu Shanshan's disappearance, the two parties become allies to solve the case.
After the apparent perpetrator Liu Min strangles himself during the interrogations, Xiao Li continues to stick close to the duo. Together, they go on to investigate the case concerning Qian Jin, Li Tianchen, and Li Tianxi, even remaining in touch beyond its conclusion. Xiao Li is also the one to personally escort Cheng Xiaoshi and Lu Guang back home after their two months of hospitalization.