Naoko Sakurai (桜井直子, Sakurai Naoko) was a college freshman and the instigator of one of Yusuke's last shown cases as a "Spirit Detective".
It eventually turned out that she had planned everything from the beginning.
With the help of two girls from the basketball club, she made it seem as if her room was cursed. Kurama could tell that there was more than one perpetrator as the footprint appeared when the room was locked, and with more than one person they could quickly dispose of the evidence.
Kurama was able to figure out her plan, and hired a Travelling demon to pose as a ghost and scare her into confessing. Then she admitted everything. Because Hidemi Hirosawa was at her college on a basketball scholarship, even if she performed poorly in practice, all the freshmen would get in trouble. Hidemi would deny it if she was blamed, and because of her actions, team morale was decreasing. As she could not quit the team due to her scholarship, Naoko decided to scare her to the point that she would stop coming to the dorm, thus the school would have a reason to kick her off the team. Still, despite their actions the three students considered themselves the true victims and refused to consider their actions as a scandal.