Tag used for Tana (Fire Emblem) from Fire Emblem, specifically when dressed in her summer attire from the Fire Emblem Heroes 2018 Summer's Arrival banner.
Can typically be identified thanks to the attire's characteristics: a magenta and white One-Piece Swimsuit, with yellow Frills on the hips, and occasionally a yellow Towel.
Note that it's possible (especially for older artwork), to depict Tana in a swimsuit without it being the one described above, in which case this tag should not be used.