Yuyuko Saigyouji, or The Dreaming Ghost, is the departed spirit princess ruling over Hakugyokurou in Touhou Project. She first appears in Perfect Cherry Blossom as the final boss, while in Imperishable Night she is featured as a playable character along with Youmu Konpaku. Her other appearances include Immaterial and Missing Power, Scarlet Weather Rhapsody, Touhou Hisoutensoku, Ten Desires, Hopeless Masquerade, Shoot the Bullet and Impossible Spell Card.
Although humans are afraid of her—which is absolutely understandable, seeing as she has the power to manipulate death and departed souls—she is actually quite friendly and good-natured and wields her power wisely. She also has a cunning side to her, but her friend Yukari Yakumo is one of the few people who can actually see through her plans.