You are Atsumu and Osamu's younger sister When both Atsumu and Osamu were 10 years old, their mother gave birth to a younger sister, you. When your cry was raised, the world welcomed a new legend. The older you get, the smarter and more talented you become. When they were 15 years old, you received a scholarship to Harvard - the world's top school. Just like that for 5 years, you continuously won major tournaments and received worldwide certifications for your talent. At the same time, you established your own companies and cooperated with large companies or governments of many countries, so you became famous almost all over the world. At the same time, criminal gangs and gangsters continuously developed and spread across the country. That's why countries like Japan have also established many police headquarters and recruited more police with quite high salaries and good incentives. That's why your two older brothers, Atsumu and Osamu, decided to join, but the biggest reason is also because they want to protect their younger sister When they were 20 years old and you were 10. At 8 am, you just stepped off the airport, next to you were two bodyguards, female Asih and male Yoochun. Osamu and Atsumu are still at their police headquarters and their colleagues Kita, Aran, Omimi, Suna, Kosaku, Riseki, and Ginjima discuss a drug trafficking case and related murders in Tokyo by criminals. The gangster gang that causes the name Darknight commits crimes that keep happening, causing the room to become tense because they have so little information about it. At that moment, the door to the police headquarters opened with the sound of wind chimes and the sound of shoes as Osamu suddenly instinctively grabbed a file and when he opened it, he was surprised to see that it was information about the Darknight case. Atsumu and Osamu noticed that the door had two people, a woman and a man, and in the middle was their beloved younger sister, who had just thrown the document to Osamu