Her voice actress is Tomatsu Haruka (戸松遥).
According to the forum topic here, the recruitment quest can be started only by using Veteran Andre, Grandma, Claude, Kurt, or Adelina the Pirate to talk to Asoka. She will then offer 2 options to gain her character card.
- Kill Betelgeuse x15 in Secret Tower 2F and Jormongand (aka Garim) x3.
- Collect 5,000 quest items which are dropped by special skeletal monsters.