|Alias||Dr. Feng Jing|
|Eye Color||Light Green|
|Other Relations||Johannes Kleeman (Close Friend)|
|Manga Debut||Line 24; Don't Cry|
|Anime Debut||Episode 9; Command|
Feng Jing (馮静 Fen Jin ) is a doctor who works at Shirase Hospital. She is one of the donors who sell blood to Johannes Kleeman, and is a close friend of his.
Feng is an adult woman with a slim build who is of Chinese heritage. She originally had long, black hair which fell down below her shoulders, but she dyed her hair light brown and cut it to lower chin-length, as she claimed that she wanted a "change of pace". Her fringe is middle parted and she has two strands of hair framing her face while the rest of her hair is tucked behind her ears. She has calm, light-green eyes.
Feng is a very kind and soft-spoken woman. She is always calm and takes everything nicely, as she can handle stressful situations in a rather level-headed manner. At the same time, she can sometimes be quite easy-going, carefree, and playful and mess around with Lee. However, she does really care for him and embraces him as a true friend. Like Lee, she doesn't want to focus much on love or romance and just wants to enjoy life. But Feng treasures and believes in familial and friendship bonds, as she claims people are not simple to just abandoning someone important.
Feng and Lee are very close, they have been friends for quite a while and Feng sells blood to Lee. Their relationship does not solely consist of selling and buying blood though, they share a genuine friendship as people who are of the same heritage. They are very comfortable with each other and Feng cares deeply for Lee, as she was seen to be happy and very excited when Lee revealed that he had become "friends" with the F Squad. She hopes that he'll become a member of that "family", too. She also doesn't care about the fact that he comes from an underground hospital, as she thinks of him as her family. Feng pushes Lee to go back to the F Squad, his "home", but she has told him that if he really doesn't have anywhere to go, she would happily let him at her place. She wouldn't even ask him to pay with his body. Feng is determined to please Lee, as she had bought a toothbrush for him and prepared his favorite meals when he came to stay over. Although Feng has stated that she does not like him romantically, she has said that she wants to sleep with him and Lee also says that he wants to try it out. However, she is also a bit afraid that their relationship will change if they do it. Still, Feng considers Lee a very important friend. She confides in him how she is always going to be there to support and help him if he ever needs it.
- Feng is the one who made Lee's alias name, "Hans Lee".
- She is seen to smoke from time to time.