Mark is one pain in the naughty kid. It's not that I-want-to-do-it-my-way kind of naughty, it's more like okay-let's-bomb-this-motherer-up kind of naughty. He is extremely naughty that his mom have to tied his leg on the pole inside their house so that he won't sneak out anymore. Mark constantly get grounded by his parents but never actually obey anyway since the whole street can hear his mother yelling his name every time when she finds out that the boy is not in his room just like how she planned. Mark speciality is to make his mom go berserk.

Mark always hated school since he was just in the kindergarten. He would cause trouble everyday like broke the vase outside the kindergarten one by one every week or even worst, threw up on someone's hair. Things went worst when he entered primary school. Mark met Jackson when he first step into his class when he was seven years old. Jackson looked up at him and smile mischievously at Mark. And from that moment on, they became best friend and also partner in crime, causing troubles around the school.

Their teachers did tried to separate both of them by putting them in different classes or even different floor. But all of the efforts were wasted and pointless because no matter how far they put distant between them two, they s remains the same. The students would be hearing the room teacher yelling something like 'Mark go back to your class' or 'Jackson this is not your class' or better yet 'Both of you, get out!'. Situation cool down a bit during the last year of them in primary school and all teachers thought that maybe they've finally grow up and stop causing much troubles to the school. But all that thought went down the drain when Mark and Jackson decided to explode huge packets of powder around the cafeteria. And worst of all, it was an itch powder.

During high school, Mark's dad thought that it would be best if he transfers his son to other school away from Jackson. He registered Mark into an all boy high school in the middle of the town with a high hopes that Mark would change to be a better boy and stop fooling around. His face dropped 360 degree when Jackson slings his arm on his neck and shouted a loud, "Hi uncle! We meet again! I missed you!".

It's turned out that Jackson also went to the same school making Mark's dad letting out a small cry. It was just the 3 months of high school and both of the badass already caused troubles that's explained why Mrs. Wang and Mrs. Tuan standing in front of them angrily. They got scolded for a damn good 2 hours and Mark swears to god his ears is bleeding. On the second year, Jackson and Mark met Yugyeom and also his Thai friends, Bambam who made Jackson's heart skip a whale long beat. After few months of getting know each other, Jackson and Bambam finally announced that they are dating. Mark can't help it but to feel happy for his best friend. 

Two of them once accidentally burnt down the chemistry lab because Jackson is a and Mark is nothing less than that too. Their class was having an experiment on how acid react with alkali in the most decent way they can do. But decent or not, Jackson accidentally spilled the alcohol on Mark's lab apron, well at least everyone thought it was an accident. Mark got angry and 'accidentally' (too) threw the busen burner at Jackson but the boy was quick enough to duck down before that thing to hit his face. Well maybe it would be better if the busen burner hit his face thought Jackson when he and other students standing outside the burning lab. The bunsen burner accidentally (again) hit the alcohol down and caused fire. 

After that 'accident', Mark and Jackson was prohibited to enter any lab in the school and it made Jackson mad. Well maybe he was just overreacted because it's not that bad though, he and Mark gets to hang around the school rooftop every time their class need to use the lab. Hm, yup. It's not bad at all.

On the graduation day, Mark and Jackson were so grateful that the school principal allowed them to graduate since they always caused troubles to the school. Little did they know the principal agreed on letting them graduate because he can't wait to see them leave the school. The students decided to play some water balloons on their last day in the school. Everyone did had fun, okay let's erase that because only Mark and Jackson had fun that day, others just got pissed and annoyed. Both of the filled the balloons with paint instead of water and throw it around the school to everyone they saw and run off quickly before the principal have a chance to take back their certificates.

Yugyeom is a street dancer, that explained the long legs and nice muscles around his figure. Yugyeom decided to bring Mark, Jackson and Bambam to one of his competition on the Friday night. And since that Friday night, Mark never fall in love so deeply like how he fell for dancing so he and the others started to founded a dance group that is kinda well known around Seoul and Gangnam. Mark, Jackson, Bambam and Yugyeom agreed on naming their team as Crasher dance team. When Mark was 19, he met a boy named Vald at one of club he dancing at and fell in love. Vald is a year younger than him but lot more matured than him and he decided to join Mark's dance team. 

Last summer when Mark turned 19, Mark and his friends went on a trip to Jeju Island, thanks to Bambam little fantasy after he watch Winter Sonata since that movie is a thing on that time. And Mark, he just too snobbish to admit that he loves to watch Winter Sonata. They supposed to stay at the island