It may not be a surprise to see Sailor Fuku as an unlockable outfit in a Japanese game, but when Grandma Lisa reveals in the ending that Annika's default outfit is what she wore as a child, and Lily's dancing during every boss fight creates a connection between Lisa and the dancer's dress, it's possible that all of the outfits, aside from the final, secret outfit, are based on things that Lisa used to wear. Sailor Fuku have been getting phased out as uniforms, but in Lisa's time they would have still been common.
