Here's why:
* "Ko wai" means "who" or "what".
* "Ra" is an intensifier, like "indeed" or "actually".
* "Kotiro" means "girl".
The phrase is missing a key element, such as a verb or a preposition. It would need to be expanded to make sense.
Possible corrections:
* "Ko wai ra te kotiro?" - "Who is that girl?" (This uses the definite article "te" before "kotiro").
* "Ko wai ra kotiro i reira?" - "Who is that girl over there?" (This adds a preposition "i reira" meaning "over there").
* "Ko wai ra kotiro e noho ana?" - "Who is that girl sitting down?" (This adds a verb "e noho ana" meaning "is sitting down").
The phrase you provided is incomplete and doesn't have a clear meaning on its own. You need to add more information to make it grammatically correct and understandable.