This is Rosie (or sometime Rose)/Akairo (あかいろ), Akai for short.

An energetic, optimistic, and outgoing , (not the brightest, but still) “La dee daa” flower girl who likes to have fun and make new friends.

Like her sister Violet, they look, play, and act familiar. Though unlike Via, Rose more extroverted and sportier. She also really cares for everyone more than herself at times and can be clumsy sometimes.At other times she sometimes can go crazy and act out of hand or aggressive. While Violet likes to befriends with every creature outside of there world, Rosie on the other hand can sometimes get afraid of them at times. 

She was born in the realm based on their imagination, the Sozo Realm (Sozo is “imagination” in Japanese, so it’s also called the realm of imagination), with her Sister Violet on May 5th, though unlike her, Rose was born at 4PM, meanwhile her sister was born before her at 4AM. They pretty stick to together when they go anywhere at most times, though they sometimes do they’re own thing.