Mistranslations. All the time. In katakana her name is Son Mina or at least it's spelt that way. Since there's no "ng" sound in Japanese, interpreting gets hard. It doesnt really matter as long as the sound is remotely close and not something like "Deung Qui-na".
But it annoys me how when writing names underneath health bars or anywhere else, she's the only one that gets her surname in there as well. Her first name is Mi-na... as in like, only "Mi-na"... though it's Project Soul that do this themselves, it confuses me.
Yun-seong's name would have probably worked better as "Yun-sung" as well =\ In katakana he's "Yunsun" while Mi-na's surname is "Son" so really, they should be different names rather than both being Seong.