1- Hatsujou- Younger bro Takao found his lifetime pair, the teacher Yuuki. https://www.mangago.me/read-manga/hatsujou/
2- Yokujou- [Spin-Off] – Big bro Hayato’s fated pair, Shirou turns out to be a rival yakuza. https://www.mangago.me/read-manga/yokujou_iwamoto_kaoru/
3- Misujou- [Sequel of 2] - Hayato somehow turns into 'Eve' type then bears lovely twins! https://www.mangago.me/read-manga/mitsujou/
4- Shikijo- [twin story] it's gonna be spicy and amazing to read if it goes according to novel.https://www.mangago.me/read-manga/shikijo/
Mitsujou