We cannot really change your username as it is linked with your OGS nickname. If you so wished you can change your username on OGS game site (or have a moderator do it) and then logging off and in again here should update it.
But not sure it is worth the hassle… And sorry about the trouble.
The characters themselves looks like they could be a Japanese name but have no real meaning, but when you pronounce it in Chinese it sounds exactly the same as 不穿内裤 ( Bù chuān nèikù ) or to go commando.
Seems more interesting in Chinese. Guess it loses a bit in translation.