Etsushimaru Yakuko

Yakuko Etsushimaru, Yakuneko or simply Yaku, is a long time friend to Yaniko and even looked up to her when they were younger. Yakuko is shown to be the most extreme case of substance abuse, and is depicted as a jaded individual after various traumatizing incidents. Her name is a reference to real-life musician Etsuko Yakushimaru.