|Full Name||Ono Haruka|
|Voiced By||Sakura Tange (Anime)|
|Novel||Volume 1, Chapter 2|
|Anime||Episode 4, Enrollment Chapter IV|
Although Haruka is older, Tatsuya is considered her "senpai" (upperclassman) when it comes to being a student of Kokonoe Yakumo. The two have struck a deal where Haruka would supply Tatsuya with information regarding incidents, in exchange for keeping her status as a Public Safety Investigator to himself.
While the anime merely hints at this, in the light novel, it is clear that Haruka becomes frustrated around Tatsuya, especially after she was assigned to find his "true identity." She is annoyed at Tatsuya's ability to read her thoughts as well as her inability to get any sort of hint as to what Tatsuya is thinking or feeling. She has tried to avoid Tatsuya whenever possible to the point where she asked for a different assignment when she was ordered to investigate Tatsuya.
Haruka is one of Yakumo's students, and most likely a source of information for him.
Haruka was one of the many students at the time, who both admired and envied Kyouko for her magic talent. Haruka's enmity towards Fujibayashi Kyouko also comes from Kyouko's intentionally dismissive and condescending attitude towards Haruka's work as a public safety investigator.
During the Nine School Competition arc, Kyouko had once asked Tatsuya who Haruka was, but upon hearing how she was public safety agent and a guidance counselor, she simply laughed at the "Part-time agent" and never brought her up again.