Kurumi Tokisaki (時崎 狂三ときさき くるみ, Tokisaki Kurumii?) is the third Spirit to appear. Due to her brutal actions, she is referred to as the Worst Spirit (最悪の精霊, Saiaku no Seirei?). She is also the first Spirit to appear as an antagonist in the Date A Live series.

Mana reported that Kurumi Tokisaki is the most dangerous Spirit ever known, having killed over 10,000 people (not including spacequake victims) personally.

Kurumi Tokisaki had used unstated and unexplained methods to personally transfer into Shido Itsuka's high school and classroom so that she could get closer to him. Her purposes and reasons for moving were simple: consume Shido Itsuka, and in doing so, gain the Spirits' mana sealed within his body. During the time Kurumi was a Raizen high school student, she almost succeeded in consuming Shido. However, she was forced to retreat after being overwhelmed by Kotori's destructive power. Kurumi had claimed that it was because she simply wasn't prepared to face her, but later argued that she could defeat Kotori if she had more time stored up.

Later, it was revealed (at the end of Volume 4) that Kurumi had a conversation with a mysterious being that made it seemed like she was talking to herself. Here, she stated her real goal was to seek Shido out in order to be able to use her 12th bullet to travel 30 years back in time and kill the First Spirit. To accomplish that, she required a significant amount of spirit mana which she didn't possess, which is why she wanted to consume Shido. Shido held the spirit mana of three spirits within him, enough for her to be able to use the 12th bullet and still have some power left over to kill the First Spirit.

Kurumi is "a girl with astonishing beauty," as described by Shido. She appears to be elegant and has very polite manners. She has ivory skin and long, black hair usually tied in long twin tails. Her right eye is red-tinted while her left eye appears as a golden, inorganic clock face. The positions of the clock hands represent her remaining "time" and are covered by her bangs, which are only revealed when she transforms into her Spirit form.

The Astral Dress, which Kurumi wears, is made out of crimson and black frills, giving her the appearance of an elegant Gothic Lolita with uneven twin tails. On her head, she usually wears a big crimson net bow to hold her hair. She also wears a red and black collar on her neck. Kurumi's height is stated to be 160cm, and her three sizes are B85/W59/H87. When not in her Spirit form, Kurumi usually tends to wear either the female winter uniform of Raizen High School or a black Gothic Lolita dress.