Su Xing and An Suwen have a fairy amicable relationship in the beginning of the story as she is always helping make medicines for Su Xing and his team. Sometime in the story Su Xing requests they become Sworn Big Brother and Little Sister, to which she agrees to. Later in the story at a time when Su Xing is having issues progressing with his cultivation, Wu Xinjie suggests An Suwen and Su Xing attempt to sign a Star Maiden Contract, something they both seem willing to do. Su Xing surprises An Suwen by giving her a sensual kiss, believing this is the only way to sign a Maiden contract.
After signing their contract, they seem to have gotten closer to one another. An Suwen becomes more emboldened, even giving Su Xing a handj*b when helping him with his cultivation.