Cloud Strife - upper left arm
Tifa Lockheart - upper left arm
Marlene Wallace - wears a large pink ribbon in her hair, which is braided into a ponytail
Barret Wallace - lower left arm
Denzel - lower left foreleg, above his bangle
Yuffie - upper left arm and on her shuriken. As far as we know, she is the only character who sports two pink ribbons.
Cait Sith - upper left arm. It is unknown if Reeve also wears a ribbon.
Vincent Valentine - lower right arm
Cid Highwind - upper left arm