Due to his upbringing in the slums and being separated from his sister for nine years, he wears women's clothing most of the time to feel closer to his sister as well as feel more comfortable about himself compared to when he grew up poor and unclean.

He has long, light-brown hair that reaches his lower back and is noted to have androgynous facial features. He is most commonly shown wearing a brown vest over a white chiffon blouse with a red ribbon, a red skirt, and long black socks.

Lin is rather impartial to social norms such as gender stereotypes, as he has been quoted saying he never understood what was so wrong with men wearing skirts if women could wear pants and generally enjoys wearing makeup and decking himself out in female attire. He has a great interest in fashion and romance stories.

He initially starts off as very frugal to pay the debt he had to Zhang at the beginning of the series, but after that matter was taken care of Lin starts to frequently shop and spend more money, though not to an outrageous degree. He does, however, have a tendency to go shop and spend money to relieve stress. Because he grew up poor, he is very conscious of how much money he has and has developed a principle to never waste food, even if he does not like it.

Due to a betrayal with his friend Feilang and the harsh upbringing he had to go through to become a hitman, Lin is self-reliant and has difficulty opening up and putting his trust in others until he met Banba and his friends. He tends to be curt when talking with others and can be at times too harsh or insensitive when considering other's feelings, but this seems to stem with his belief to face a hard fact at face value than to sugar coat the reality of the situation.

Lin lived his childhood with his mother and younger sister in the slums of China. His father indulged in drinking and gambling, and at some point, he left his family and his remaining debt behind. Lin often had to go out on the streets to find scraps of food to eat.

Men from the human trafficking business approached Lin's mother every day to ask her to sell her children, which she refused. Seeing his sick mother desperately try and support him and his sister over her own well being, Lin decided to sell himself to the human traffickers.

At age nine he was brought to a facility to be trained as an assassin, filling out one of the empty spots of a recently passed trainee. He was then introduced to his roommate and partner, Feilang, who became his first friend. Together, they helped each other out during lessons and training over the next four years. Lin and Feilang grow close over that period of time and vowed to work together after they made it out of the facility. However, the day of their exam, the two were locked into their room and weapons were laid out for them. They were ordered no one would leave until one of them killed the other. Lin initially attempted to find a way out, when he was attacked by Feilang. In a panic, Lin grabbed the nearest object near him and attacked Feilang with it, making a deep cut on his face. Feilang seemed to have died, and thus Lin was allowed out of the room, and shortly after he began his life as a hitman. About a year after graduation, he was sent to Japan to work under the Kakyu Association's executive Zhang.

(Source: Wiki)