Behind pastel braids, marshmallow bunnies and teddy bears, lies the "sepia ink". The girls of the Sad Girls Club dominate the Carr girls' boarding school, with their enigma and a sad veil of ruthlessness. However, Rikka is determined to enter their world, observing every move and witnessing the most macabre of shows. But what secret dwells in Rikka's mind?

Rhea Doll is an author of short stories and novels. With her artistic versatility and innovative spirit, she weaves narratives that make the characters seem to come to life. Behind the scenes, she is the mind that has drawn the map of Rhaetia, a dream place located underground.