Thread:^achie^/@comment-1298206-20120604201652/@comment-1298206-20120606014045

I was thinking of it more being like who would the little girl fight xD

Tite Kubo (the author of Bleach) said "...grinning, an act of intimidation." I guess Gin's trying to show that he isn't at all intimidated by his enemy and finds it amusing or he's trying to intimidate them by making them wonder why he's smiling.