Luca is a very cheerful girl who was childhood friends with Croix. She works as a Dive Therapist in Rakshek and is extremely knowledgeable in all matters related to Diving and Dive Therapy, being the only one who can heal the IPD Reyvateils that later join Cloche's fan club. She has strange tastes in cooking. Her speciality dish is Chalon de Trois and Croix often indirectly calls her quite bad at cooking it. She seems to harbor a lot of secrets under her cheerful exterior, proving to be rather pessimistic and angry at times. Her Japanese surname "waath" means "revive" in Hymmnos language.