At a young age Kim Taehyung and his best friend Jeon Jungkook agreed that if they were not married by the age of 30 they would marry each other. Many years later it is time to fulfil that promise, except Taehyung was a successful FBI agent. Jungkook? A notorious Mafia leader. - Taekook fanfiction! Dominant top- Jungkook Submissive bottom- TaehyungAll Rights Reserved