I don't know what Boxbox is, but I can suggest how to make a name sound "smooth".
Vowels often do it. Syuura, Loriea, things like that. There's a site called Rinkworks that has a name generator, and it has a template for vowel-heavy names, which might help.
It looks like two of the names you mentioned are actually Asian. Kaihua looks Chinese, and Porogami has elements of Japanese. (It looks like it might've mixed our phonetic pronunciation of the English word "polygon" ("po ri ga n") with the word "kami", which literally translates to "divine". ... Kami is written as "gami" after certain phonetic sounds, it's complicated.)
So that might be another idea. Look at some Japanese or Chinese words and either pick one you like on its own, or use the phonetic elements to come up with a nonsense name with an Asian sound.
Good luck!