Mo Guan Shan is an attractive boy with natural fluffy red hair and red eyes. He has a white peach skin tone. He's always seen wearing white and yellow based clothes. He has both of his ears pierced and outside school he often uses earrings. Although most of his classmates see him as a school bully because of his outside appearance and bad temper, in reality he is more of an outcast than anything else. His problematic behavior at school is most likely caused by the fact that he thinks people are thinking lowly of him. He's actually a very sweet boy underneath and seems to share a very lovely and stable relationship with his mother. For unknown reasons his father is in prison but he seems to believe in his innocence. He shows a tsundere side with He Tian. He is either mad at him for no special reason or gets easily flustered when the He Tian touches him or initiates any type of physical contact.
Mo Guan Shan starts as a "bully" who picks on Jian Yi and later physically hurts Zhan Zheng Xi. Shortly after He Tian, despite being friends with Jian Yi and Zhan Zheng Xi, begins to develop feelings for him and following him around, much to Guan Shan's disdain.
When his first kiss is stolen by He Tian he gets very angry assuming he was only making fun of him, to the point of crying leaving a speechless He Tian behind. After this event He Tian refrains from being too pushy but still pursuits him anyways and despite everything, Guan Shan seems to start seeing him in a different light by being very aware and acting flustered at any kind of physical contact with him.
When Mo Guan Shan is framed by She Li for assaulting a girl he is very surprised to see Jian Yi and Zhan Zheng Xi helping him by clearing his name thus making him start a more friendly relationship with the both of them. When he sees an injuried He Tian after fighting with She Li for his sake he is greatly touched and they share a moment where they interlace their fingers together and he uses his own shirt to wipe He Tian's blood.
When Guan Shan accepts to go dinner with He Tian after finishing the job He Tian has got for him and the restaurant they go happens to be same restaurant his father used to own when he was a child he gets traumatizing flashbacks of his childhood and runs away. He Tian goes after him and sees him having a break down. At that moment Mo Guan Shan seeks He Tian for comfort, having the latter stay by his side until the end and eventually getting him home safely.
Despite his initial hostility towards He Tian, he seems to care a lot about his safety to the point that when he thought He Tian was in some kind of danger he didn't waste a second running to his house to save him, confessing he doesn't hate him that much in the process. He Tian seems to interpret this as a love confession. It all ended up being nothing but a misunderstanding.
In chapter 240, Mo Guan Shan takes an early leave of school to visit his father in prison. Here we learn that his father never allowed Mo Guan Shan to visit him before, this being the first time in years he has seen his father. Between tears he shows his resolve to become a courageous and upstanding person like his father is.
- He is a good cook, noted by He Tian, Zhan Zheng Xi, and Jian Yi.
- His family used to own a restaurant, so that's probably why he's a good cook.
- He's seen wearing an orange bracelet in many chapters and in different illustrations.
- Official illustrations hint that He Tian and him are a couple in the future. Some of them even hint something before that.
- He Tian gave him the english nickname of "Don't Close Mountain" and "Little Mo".
- He Tian gave him a giant plush sandwich for Valentines Day.
- He is still keeping the Adidas jacket He Tian lent him.
- He has a very scientific Zodiac book.
- He has pierced ears and owns a pair of earrings given to him from He Tian.
- His red hair is natural, not dyed.
- He's always seen eating sandwiches.
- He likes sunflower seeds, and has stuck them to the classroom windows before using 504.
- In one of the official illustrations, he and He Tian are shown to be wearing matching couple rings.
- He owns a bike and rides it home/school sometimes.
"What is it to you? Are we suppose to be familiar?" — Mo Guan Shan to He Tian
"The other party is gentle, caring and understanding?… What is this nonsense?" — Mo Guan Shan
"Bro... You... aren't in love, are you? — Mo Guan Shan's friend about him
"I was kidding earlier! He Tian! I don't actually hate you that much!" — Mo Guan Shan to He Tian
"...I've been doing very well... I've been taking good care of mom... I go to school on time... and I am able to make friends with the people in my school... more than anything... I will become someone courageous and upstanding like how father is..." — Mo Guan Shan to his father