When Kai Lunao was on his way back home from school, he picked up a mysterious BL book titled, "The Gold Knight." Shortly after reading the book, he died from a fire. Shockingly he transmigrates into the book! Kai reincarnates as the hero's childhood best friend who was destined to be left behind by the hero of the book. His fate was to fall into an unrequited love with the hero who was the protagonist of the book. However, Kai adores the Villain! Kai does not want to fall in love with the hero, instead, he wants to pursue the Villain!

So in this au giyuu found out that he had feminine parts and that he was a 1/2 demon right before he became a hashira and he thought that it would affect him that much. It was true that it didn't affect him that much but after one night l when uzui had thrown a party for all the hashiras giyuu and Sanemi unexpectedly had sex and 3 days later giyuu ask kocho for help and then the result came out giyuu was pregnant. Shinobu ask giyuu what he would about the baby an the corps he said that he was going to retire after 3 or 4 months. That what he did and it had been 4 years since that day and giyuu visits muzan and the upper moons every now and then. When giyuu told the master about this he agreed with it and told him that he could still come and visit the headquarters any time he wanted, he also told giyuu that he could have the kakauchi surround the him in secret then he retired and had the baby. Giyuu was relieved about this The baby was a beautiful Girl, she has pretty much all of giyuu traits except for the eye color and some of her hair was white because of Sanemi traits. Never the less giyuu managed to raise her and she was a beautiful and strong girl. Giyuu named her crystal