My dear friend
Currenly, there 4 Keiko's in the game: Keiko Onori, Keiko Eri, Keiko Yui, and Keiko Suzuki.
I'm afraid you have to be a little more specific on this one
Best wishes,
Smartass dev.
Well, but I can guess you're probably refering to Onori. The answer is simple. it's a bug. You've actually seen all 16 CG in her rl2, but renpy didn't recognize that because of some mishap in the code.
This was fixed in v0.09