It's an original comic by the name of Wicked Witch. Yuri is a snake witch, one of Gorgon Sisters, Euryale - hence the name. Angeline is an adventurer, I think? It's a long time ago and I didn't know about the artist at the time to order the book. It's Thai comic, but artist used Angeline-san instead of Miss Angeline... Language barrier, man. Yuri used to call Angeline Onee-sama too.