Park Jaebum

He's 35 years old and the Appa of the Park family. He has two biological sons, Yugyeom and Bambam, and two adopted sons, Mark and Youngjae.
Even though he became a parent at an early age, Yugyeom, their firstborn, was a beloved child from the beginning. Even at such a young age the both of them managed their little family perfectly so that they enabled their children a sheltered life without any worries.
Jaebum works as the CEO of his own company and owns enough money to finance his family a penthouse where everyone has enough space and room for themselves.

Jaebum is a cheerful, lively and caring parent. He adores his children and loves his wife very much. His family is the most important thing in his life and he tries to be at home as much as possible to be there for his wife and kids. He likes his job but when he comes home from work, he replaces his suit by plainclothes, let the work work be and spends his time with his kids. He loves to jostle playfully with his kids or to play video games with Yugyeom and Jackson even though he mostly loses against them.
He's a born family man and the Appa to whom the kids are looking up to.

Park Jinyoung

He's 34 years old and the Umma of the Park family. Yugyeom and Bambam are his biological sons but he loves Mark just as much as them. Youngjae, who lives with the Park family since he was nine, also has a special place in Jinyoung's heart just like his own kids.

Jinyoung is a caring Umma who hold a protecting hand over his loveable sons and looks after them to guard them through life. Sometimes he gets a bit too protective but will be restrained by his husband if he overdoes it.
His husband is his strong shoulder to lean on. Jaebum is there for him for already more than 18 years. When Jinyoung was 15 3/4 and Jaebum already 17, the two of them had met for the first time. Back then Jinyoung had a huge crush on Jaebum, a handsome and popular dancer and kingka of his school, but didn't admit it nor confessed to him, he rather started a fight with him because Jaebum and his friends presume themselves to call Jinyoung and his friends' dance practice room their own.
At that time Jinyoung's team and Jaebum's team had a big public dance battle to decide who's the better dance group and which team is allowed to use the training room further on. Okay...it was rather like a student street battle but a lot of people actually came to see the two opponents fighting.
In the end Jinyoung won the battle and his group was officially allowed to use the training room which was the only room where he and his friends could practice with the little money they had. It was just a small basement room but for Jinyoung and his friends was it the only opportunity to fulfil their dreams and passion.
Jaebum, back then, was very impressed by the passion of that cute little boy so he started to get interested in Jinyoung and followed him around. Jinyoung was very confused at first and didn't know how to react at his crush being suddenly interested in him even though he won the battle and kind of dissed Jaebum, but as time past by the two of them got close, Jinyoung grew confidence and finally confessed to the elder. Jaebum was confused back then because a man who had feelings for him was something absolutely new for him but he knew that the talent of this cute little boy wasn't the only thing he was interested in and also his racing heart whenever he saw Jinyoung wasn't something what friends would feel for each other, so the two finally started dating.
At the very beginning it had been kind of awkward because of being with a guy was something really new to Jaebum but they had quickly overcome that state and became a normal loveable couple and later on an even married couple.

Now Jinyoung works part-time as a nurse at the nearby hospital and is the rest of the day at home with his kids to cook for them when they come from school, to undertake something with the younger ones and to just be there for his children because even though they aren't little kids anymore they still need their Umma sometimes to talk about things to reduce stress or to ease themselves.

Park Mark

(I'm sorry, the last name Park and Mark's first name Mark sound just too stupid together....but I can't do anything about it >< Park Mark *suppresses her laugh* :'D)
He's 21 years old and the adopted son of Jaebum and Jinyoung. His birth parents gave him away when he was still a newborn because of an unknown reason. Since then he has lived in an orphanage where he didn't grow up like it was supposed to be for a little child. His surroundings were cold and heartless. That's one of the reasons he's a shy guy who lives kind of secluded and isolated from others.
Mark got adopted by the age of eight. He loves his 'new' parents and his little Dongsaengs very much and in the presence of them he talks a lot more than he does with others but he is still very quiet and introverted.

The only thing in which he blossoms is dancing. It's like he has inherited the passion for dancing of his adoptive parents. That's why he's currently attending dance training to become a choreographer. One day he wants to earn his own money through dancing but till that time has come, he's staying at home where his parents support him with expenses for his apprenticeship.

As mentioned above, Mark is a very shy and introverted guy but even though he lives in his own little world, he has fallen in love with their neighbour from the apartment beneath, Jackson.
Jackson is the exact opposite of Mark. He's loud, talkative, loves it to be among people and to make new friends. He also often talks to Mark, who then doesn't respond with more than just a nod or a quiet 'hm'. But for Mark it was love at first sight. When he saw Jackson's smile for the first time, he has fallen in love so hard that it even hurts now to see his crush with his younger brother Bambam.
Yes, Mark is jealous of his six years younger Dongsaeng and he feels bad about it but he can't stop it. He never felt anything so strong like the feeling he has for Jackson. But confessing is out of the question. Never would Mark confess to his crush and run a risk to be laughed at for his feelings. He rather enjoys the mornings when Jackson comes upstairs for breakfast or the noons when he comes to help Bambam with his homework. The little moments when Jackson greets him with a smile are enough to make his day complete.

Park Yugyeom

He's 17 years old and the firstborn of Jinyoung and Jaebum. He has, just like his Appa, a cheerful and brightly personality with which he amuses the people around him. One of his biggest charms is his cute and innocent eye-smile.
He's still a student and very popular at school. Just like Jaebum had been, he is also some kind of kingka at his school. The girls are crazy for him because he's so cool and handsome and the guys want to be his friend, but Yugyeom puts a brave face on people like that who just love his popularity. He has his small clique of friends with whom he hangs out at lunch but his one and only best friend, he is very close with, is Youngjae. The two of them know each other since they were little children and went through thick and thin together.
 

Apart from Youngjae, Yugyeom is also very close to his brothers Bambam and Mark. He loves his older Hyung like a real brother even though they don't share the same blood and they are totally different. When Yugyeom was still very young, he had been afraid of thunderstorms and whenever a thunderstorm was giving him a sleepless night, he would crawl under Mark's blanket and snuggle into his Hyung. Even now Yuygeom sometimes snuggle himself into his Hyung's bed like the old times but not when he's afraid of the thunderstorms - because he isn't anymore - but rather when he misses his Hyung and wants to cuddle with him. The two have a very close relationship so that Mark won't mind waking up next to a dozily Yugyeom who kicked everything out of Mark's bed but Mark himself.
With Bambam, Yugyeom is also very close. He enjoys playing Wii with his cute Dongsaeng who frets whenever he loses to his Hyung. They often undertake something together like skateboarding or just meeting at their favourite café to eat and talk a bit. 

Park Youngjae

He is 17 years old, same age with Yugyeom and his best friend. He is not Jinyoung's and Jaebum's biological son but got adopted by the age of nine when his parent's died in a car accident. His parents and Yugyeom's were best friends back then and after they had died, Jinyoung and Jaebum didn't hesitate to adopt Youngjae instead of letting him grow up in an orphanage. Youngjae was always part of the family and so he became officially the son of Jinyoung and Jaebum. Of course they can't replace his parents but he's already so close that he calls them Umma and Appa. With the Park family, he found happiness again after his parents death.

Since he has been living with the Parks and moved in, he shares a room together with Yugyeom. It's not that there aren't enough rooms for Youngjae to have his own but after his parent had died he felt very lonely and so Jinyoung and Jaebum decided that it would be better for him to sleep in the same room with his best friend instead of sleeping alone. Yugyeom hasn't had a problem with that and so they still share one room. That's also one of the reason, they're so close.
But that closeness isn't something good at the moment. Youngjae has this weird feelings for Yugyeom for some time already and they just won't go away. He doesn't want and also isn't allowed to have this feelings for his best friend, so he tries to bring some space between Yugyeom and him but it isn't really working because Yugyeom is really clingy to him, to the detriment of Youngjae.

Compared to Yugyeom, Youngjae is a shy nobody who is not that popular among girls and who prefers a book over a date with a hot girl....what also has something to do with the fact that he's in love with a guy.
He is also a talented cook who often helps his Hyung Mark or his Umma with the dinner. He generally helps a lot in the house because he wants to give Jinyoung and Jaebum something in return for affiliating him in the family.

Park Bambam

He is 15 years old and the Maknae of the Park family. Bambam is just his nickname. His birth name is Kunpimook, a thai name, because Jaebum and Jinyoung both have a deep connection to thailand. Thailand or rather Bangkok was their vacation spot when Jaebum proposed to Jinyoung. He proposed in the year 1998 when Yugyeom was barely one year old. And because it was till then their second happiest moment in life - after Yugyeom's birth of course - they decided to give their second child a name related to this moment. That's why Bambam got unlike Yugyeom a thai name.
Kunpimook or rather Bambam is a cutie who often gets pinched in the cheeks because of his cuteness. He is Umma's little boy whom he protects carefully.
Bambam has a bright personality and is a nice and sweet boy. He's his brother's little Dongsaeng who sometimes gets laughed at and isn't taken seriously because he's just too cute if he gets upset.

He is single by now but has a small crush on their four years older neighbour Jackson. Jackson often helps Bambam with his homework if he's visiting the Parks and that was also when it happened. Jackson's kind and patient way of explaining difficult things to Bambam is what enchanted him and has let him fall in love with Jackson. Also Jackson's way of being, brisk and candid, and his carefree, beautiful smile were reasons to fall in love with him.
But since Jackson sees Bambam just as a cute Dongsaeng, he would never confess to him. It's just a small rapture which will go away, at least Bambam hopes so.

Wang Jackson

He is 19 years old, neighbour and also close friend of the Parks. He lives alone in his apartment one floor below the Parks since his parents have kicked him out because he didn't want to take over his parents' company and instead of it, he has wanted to become a media designer.

Because he's not the best of a cook and generally not the best in living alone without someone who cares for things like doing his laundry, cooking for him, cleaning the apartment etc. - things his parents once did and he now have to do by his own - he often eats at the Park's apartment. He loves the Park's food, especially Mark's because he's a very good cook. Jackson envies Mark because of his talent which Jackson definitely doesn't have. He is also envious of the beautiful and supporting family Mark has, that's why Jackson often comes upstairs to spent his time with the Parks.
After his day at the university ends, he often picks up Mark at the dance studio and drives him home because they have the same way home and the time of their end of the school day is mostly similar.
Then he usually spends the rest of his days at the Park's, helping Bambam with his homework, playing video games with Yugyeom, upgrading the website of Mr. Park's company - who is already on first name terms with him - or he just simply sits in the kitchen and learns for his exams while Mark is preparing dinner.

He has an extroverted character and talks a lot. He loves to be among people and isn't able to live alone for the longer term.
He's a friendly neighbour who sometimes seems a bit pushy to people who don't know him but to his friends he's a loyal and reliable friend who is always there for them.
Sometimes he crosses lines without noticing it but it's just his normal way of being. For him it's normal to hug somebody after the first meeting or to speak to people who he don't know to make friends.
He is maybe a bit naive but he just enjoys living.