Yui

Yui is a little butterfly girl that can make you walk faster in the overworld by giving her 10 sticks.

You can recruit her by giving her 10 sticks again.

Her quirk in battle is being a sad twelve-year-old girl, and therefore she is very weak.

She has a few healing moves and debuffs, most notably making the enemy sleep, potentially losing a turn.

The game itself describes her as:

"Hates walking. Talks slowly and has a shy voice. Always looks sad and a behaves bit awkward."