Description
Hyūga Keiko (日向けいこ, Hyūga Keiko)
Keiko is a member of Konohagakure's Hyūga clan and Hinata's twin sister. Since she was born moments after her sister, Keiko has been branded with the clan's curse seal, thus marking her as a member of the Branch family. After being kidnapped in her youth Keiko swore to train so she is never put in that situation ever again. Unlike her twin Keiko is easy to rile up and has a short temper, causing her to often start fights with others.
In case anyone ever wondered why I asked for Keiko to have white eyes. The byakugan literally means white eye and the reason why a Hyūga's eyes are meant to be so odd (and a reason for bullying as seen in Naruto: The Last) is because their eyes are ghostly white as opposed to the beautiful pale violet.
Also the way I understand the curse mark is that if you are a branch member than your children will be branch members. The only reason why Hizashi got branded is because he and his brother were the firstborn sons of the Hyūga clan head and to avoid clan headship inheritance problems the youngest got slotted in the branch family. But had they had an older sibling they would have gotten away with being Main branch family members together. At least that's my take on it. Hence Keiko being branded with the seal but Hanabi remaining in the main branch.
Art © Oriiwu
Hyūga Keiko © Mewrlise
Naruto © Masashi Kishimoto