Ouka_Fan01 said: Yoshika, (because of her hair,) Erica, (because of her hair and relaxed look,) and Lucchini, (because of her fang, cat ears, and ribbon.)
Pretty sure the middle girl is Takei Junko and the girl on the right is Nishizawa Yoshiko. Junko is always pretty chill and Yoshiko has cat ears and is excitable.
It also makes a bit more sense that Mio's old Fuso comrades would be at her wedding.