Lee Kusul and Lee Jinkyong.
Kusul is the older sister, but she's also the smallest of the two.
Before you go all 'oh look, more characters with no story blahblah'
Actually, the do have a story. It's also nearly finished with. Can be found here : [link]
Ah, I changed some stuff from the original base. Not a lot, but enough that it's noticeably different.
Base by: ~DeadTreachery-Bases