They are both relatively quiet, intelligent, and thoughtful. L'eau is more of an adventurer, always curious and wanting to know everything there is to know. Koi is more meek and more of the book worm type; he is patient and wise, while L'eau is sharper and a quick thinker.

Their designs were inspired by a few beautiful koi (hence the name) fish I saw at Canada's Wonderland (which was awesome, btw). Koi's back markings are a bit intricate and will probably be hard to recreate, but I don't care. I like him. :3