Son Chaeyoung is an 18 year old living in Seoul, Korea. She attends Hanyang University studying Music and lives with her 6 adopted brothers. Park "Jae" Jaeyung, Kang "Brian" Yongyun, Han Jisung, Seo Changbin, Kunpimook "BamBam" Bhuwakul, and Yoon Dowoon. All 7 of them are orphans, only having each of them to rely on. To survive, all of them took up battle rapping to survive, except for Dowoon who is a drummer due to his anxiety. It was a job with high risk, but even higher rewards. Each of the rappers had their own solo identities as rappers, but they did also come together to do group raps, being collectively known as Jackpot. All of them were Out of the 6 of them, Chaeyoung was the youngest, softest, and smallest one of them all, leading to her 5 brothers to all be over protective of her.

One late night after a solo rap battle while sick, Chaeyoung collapes in the street on the way home. Chaeyoung wakes up the next morning in a stranger's house, and an attractive stranger at that. Myoui Mina.

Myoui Mina is a 21 year old Japanese transfer student attending Hanyang University as well, studying Medicine. Mina is also the unwilling heir to M-Meds Korea, the Korean Branch of M-Meds, Japan's biggest medicinal company. After one late night of studying at a library, Mina stumbles across an unconsciouss Chaeyoung. Mina brings her back home and nurses the young girl back to health.

After their odd meeting, Chaeyoung finds herself running into Mina more and more and eventually spending more and more time with her, eventually developing a crush on the older girl. This crush causes much controversy in the family, with all 6 of Chaeyoung's brothers against her feelings for Mina. 

Will Chaeyoung's affection for Mina tear this family apart, or will their feelings for each other sway the minds of Chaeyoung's brothers.