(ABO settings, romance novels, if you don't know what ABO is, check it out on your own, don't comment if you don't like it)
Sibling love, in college, Hao Jing was a top Alpha who was differentiated at the age of 15. Jian Jian didn't know her second gender until she was 18. She couldn't accept it and finally chose to hide her true gender.
Intention: Try the effect of ABO setting on romance