When Rishi said Chiizu was her oldest OC, Rishi lied. Rishi's sorry. Keiko is Rishi's oldest OC.
So...about Keiko. Her full name is Keiko Nara, and is Shikamaru's older sister. She doesn't really do anything in the storyl...well, that's (SPOILER FOR THOSE WHO HAVEN'T READ WHY SHIKAMARU IS LAZY) because she's dead.
Um...enough about that.
Keiko's personality is based off of my own, for two reasons. 1) I wrote it at age 12, in seventh grade, and 2) becauase my little brother, Taku-Taku, reminded me strongly of Shikamaru at the time, so I made an OC to fit everything.
Why Shika is Lazy was pretty popular, now that Rishi thinks about it...