I am Jun Lin, the poorest and most down-on-his-luck prince in the capital. Yin Yin, an assassin from the martial world, originally intended to take my life for the bounty, but I turned the tables on her, and she became my personal hidden guard. With her protecting me, my life is safe, but my blood pressure and debts keep soaring. This adorably clueless assassin has a peculiar way of thinking and can always bewilder people with her twisted logic when doing the accounts. Cute yet stubbornly serious, she and the poor prince embark on a hilarious everyday life together.