Chie Arai serves as the student counselor at the school where the series takes place. Her first name is Chie, and her family name is Arai. The first kanji in her surname can be given an alternative reading that makes her name a reference to the philosopher Friedrich Nietzsche, a detail noted in supplementary materials about the series. She is an adult woman with neck-length black hair and red or purple eyes. Chie is also recognized for having an excellent figure and a large bust, which becomes a notable physical trait during scenes such as a swimming pool episode.

In her role as a counselor, Chie is the person to whom both students and faculty, particularly the teacher Nozomu Itoshiki, bring their problems. She is often shown listening to Nozomu’s frequent complaints, pessimistic outlooks, and suicidal breakdowns, providing a form of support even as he admits to finding her terrifying. Her personality is defined by a calm, collected, and orderly demeanor that can silently intimidate those around her. She speaks with precise, sharp, and unsparing words, yet her directness is often well-received. This tendency for frank and dominant speech extends to a clear sadistic inclination, and she is frequently depicted rebuking and dominating various masochistic men, displaying what has been described as a queenly or SM-like presence. Her dominant nature allows her to exert control over male characters and compel compliance with her demands. For example, she uses her intimidating presence to force the anxious Nozomu to perform tasks like retrieving the truant student Kiri Komori.

Chie's role in the story is primarily as a supporting figure within the school environment. She offers a grounded and authoritative presence against the series' more absurd elements. Key relationships include her interactions with Nozomu Itoshiki, whom she counsels and often commands, and a notable friendship with the student Kiri Komori. In the anime adaptation, she shares several scenes with Kiri, such as washing together in the sports equipment shed and playing games, indicating a particular fondness for her. She also has professional interactions with other students, once reporting to Nozomu about the student Fuura Kafuka falling into a tiger enclosure at the zoo. There is a subtle, unconfirmed implication within the series that she may have used her dominant personality to work part-time in adult entertainment. Her role was expanded in the anime version, where she appears in almost every episode, in contrast to the original manga where her appearances are less frequent.