Actually, Yuri is more of a mix of all three dere types - dandere, kuudere and a yandere. Her default dere-type is a kuudere. She's mostly on her own and actually likes it that way, often wearing a stoic expression on her face. Her secondary dere-type is a dandere, as once she becomes involved in anything social, she becomes a nervous wreck and becomes shy about everything. Then when she really comes to care for someone, like MC or Natsuki, she will do anything to protect or be with them. (I say Natsuki as well since her line 'If anyone even thinks to cause you harm, I will unleash hell upon them'. This heavily implies that Yuri might be yandere for Natsuki as well.)