A brief explanation on the AU that has been used. I'm sorry, I should have explained it better. orz

Pistilverse is an AU mostly used by Korean fanfic writers,

In this AU, a human is born as a calyx. Once this human comes of age, he will either turn into a stamen or a pistil. If he is a stamen, he will have have a specific flower, if he is a pistil, a barren tree grows (kind of like a tattoo) on his back. Once a stamen and a pistil sleeps together, the stamen's flower blooms on the pistil's tree; how many the flowers are depends on how many times they slept together. Explains why Taehyung has different flowers on his back, meaning he slept with different people; and how Jin does not know what his flower is until he slept with Taehyung. If the tree becomes full, those flowers wither and it becomes barren again.

Think, concept of planting a seed, and then it grows into a beautiful flower.

"I want to do with you what the spring does to the cherry trees."