Yang Jinghua comes from an ancient line of famous exorcists who worked for the emperor in ancient times. Unfortunately, the family business has long since dwindled, and after his parents died when he was young, Jinghua lived a life of poverty, where he worked part time as both a fortune-seller and computers repairman.
On March 28, 2017, during an outing to gather junk parts for those repairs, he encountered Duanmu Xi. He'd seen the man in a car once before, but this time it was close up, and the other man was fighting an evil spirit. At the time, Duanmu Xi was shocked that Jinghua could see the spirit, and soon after that the two parted ways, with Jinghua mostly shrugging the encounter off.
Later that same evening, Jinghua was struck by a truck and passed away. However, death was not the end, as he instead became a ghost. He was still in the hospital when Duanmu Xi arrived, and he offered a choice. Jinghua could either stay as he was and eventually lose his sanity, or he could form a pact with Duanmu Xi and become his 'Spirit Shadow'.
After dying, he transformed into a youthful version of himself. At this time, Duanmu Xi was able to recognize him as his 'very first friend' from the past, though Jinghua was unaware of the other's identity.
Since forging a pact with Duanmu Xi, his life has become filled with unexpected adventures and dangers from every corner. When Jinghua gets into a serious fight, he finds himself transforming into an adult version of himself, which highly resembles his ancestor Yang Ning.
Because Jinghua is a direct descendant of Yang Ning, a powerful and famous exorcist from a thousand years past; he can wield the sword Luoyue, which possesses the ability to seal spiritual powers, and was created to punish any Yangmingsi that caused harm to the world. The sword and its sheath were forged by Yang Ning, who cut off his own left arm to do so.
Note: In the Japanese dub, the following names were localized:
Yang Jinghua as 'You Keika'
Yang Ning as 'You Nei'
Duanmi Xi as 'Tanmoku Ki'
Luoyue as 'Rakugetsu'
