Snow Sprite Six-Star Evolve Gem

The gem with the purest Astral power can Evolve the Senshi "<Snow Sprite>Yui" to a higher tier.
It can be given to Senshi through the "Give Gift" button in the Senshi interface, and can increase the tier up to Six-Star.
You must own a One-Star Senshi before you can give gifts, and you can only increase one tier at a time. After Evolving, the existing star energy will reset to zero.