A "wannaboo" is a portmanteau between "wannabe" and "weeaboo." It is almost synonymous with a weeaboo, but indicates that the individual is more obsessed with wanting to be Japanese more than just being obsessed with the culture alone.
"Man, Akwasi is such a wannaboo. He's trying to take Japanese classes to fit into Japanese culture."
by notjapanese February 23, 2014