The "Youkai of Boundaries". Phantasm Stage boss of Touhou's Perfect Cherry Blossom and later a recurring playable character.
A powerful youkai of at least 1200 years of age, reputedly older than Gensokyo itself. Nominally responsible for guarding the border between Gensokyo and the outside world, but is frequently sleeping or slacking around, leaving her work to her shikigami Yakumo Ran and Ran's own shikigami Chen.
Yukari has the power to manipulate boundaries, as well as create gaps, leading to her nickname "Sukima". However, she frequently holds back her powers and most of the time she only goes as far as playfully dragging any unsuspecting human from the outside world into Gensoukyou.
Besides her servants, she is friends with Ibuki Suika, Saigyouji Yuyuko (whom she knew from as early as the latter's days as a human) and Hakurei Reimu (the other barrier guardian, whom she sometimes pesters). Also hinted to be Morichika Rinnosuke's business partner and supplier of items from the outside world. Yukari has an as-yet undefined connection to Maribel Hearn.
