My names for the I'ee are easily the simplest of the names I've came up with over the years. I simply go for something disarming and cute, like Sammy and Sally. In Yui's case, she's named after Yamatai's leader, of whom the Ee'ith are like a fanclub for; naively eating up the proclaimed image of a glorious, noble organisation that keeps the peace. Gut-Stripe is named after her preference of painting her body with elegant warpaint, which once upon a time, probably was some unfortunate opponents guts.
The I'ee language, and how I name things with that, is a little more complex. They have a number of sounds which have vague meanings attached to them, and by stringing together these sounds into 'words', they ascribe more definition to what they say.
Ee = Something familiar, like family, home, etc.
Thus, Ee'ee means home more specifically. Ee'ee'ee means family specifically.
Ironically, even though Ee is in the I'ee's species name, I actually haven't determined a definition for 'I' in their language yet.
My immediate concern at the time was thinking up a name that could feasibly be said by a creature with no lips or proper vocal cords.
Some more exotic examples of names I've came up with are Aghretta and Avecitine; both female names. I came up with them by playing with sounds in my head and stringing together those which sounded name-like. Names beginning with A are what I tend to end up with, strangely.
A bit more in-line with the Japanese/anime theme of this website is my made up name Kipahsunah. Kipahsunah was the name I came up when I was doodling creatures you might see in a side-scrolling platformer. Since Mario is easily one of the most well recognised platformers, I made up a nonsense name that sounded vaguely Japanese to me.
Kipahsunah eventually became more of a proper character than just a nobody enemy, though.
In other cases, I take a word that relates to a character I'm making in some way and play with it in my head until it becomes something more interesting. For example. Opioni comes from 'opinion', Quela comes from 'que' (the spanish word).