There is a legend that the most priceless treasure in the world is hidden in an old castle in City A, but the key to the treasure is unknown. Until one day, an exchange student named Anze came to Lanying College. With his arrival, the entire Lanying College was shrouded in gray clouds, and the school also underwent earth-shaking changes. The mysterious Kubster sent a letter asking the school to find the legendary golden key. He Ying and Shi Yi embarked on this bumpy treasure hunt. I originally thought that after finding the Golden Key School, I would be able to return to the original peace, but it was not the case. After going through a lot, watching her sister suffer from neurasthenia, and the person she loved most was injured because of her. He was only 0.1 Millimeter away from death due to a heart disease, and she collapsed from zero. If I could, "I will be your heart and struggle with your heartbeat."... What finally opened this priceless treasure was the beautiful rose tattoo pattern on her own back. Blood-red roses bloom with enchanting beauty...