Haru Chitose, a 16-year-old Sapporo native, performs as a senior idol in unit H☆E☆S within Ongaku Shoujo. She exhibits a spoiled, greedy personality with occasional lapses in common sense, particularly in her dynamic with fellow member Eri Kumagai, whom she engages as an enthusiastic yet oblivious partner. Standing 155 cm tall, she sports multicolored hair and violet eyes. Her interests encompass free climbing, American/Hollywood films, and American comic book heroes. She holds strong affection for Eri among her favorite things, while actively disliking ghosts and earplugs. Her theme color is red (#CB0A0A), and she specializes in rock music.

Her backstory originates in a 2015 short film where, after transferring schools, she discovered Eri was the anonymous singer "Noconoco"—whose music Haru admired. Haru persistently pressured the stage-frightened Eri to perform live, catalyzing their relationship. During group activities, she relies exclusively on stylist Tsubasa for makeup, crediting Tsubasa's work for giving her a "zippy and peppy feeling" that excites her about idol duties. She frequently engages in physical expressiveness: poking Eri’s waist during reading sessions, sleeping beside her, or grabbing unit-mate Sasame Mitsukuri during fan espionage. She also displays flustered reactions, notably panicking when encountering a naked girl during an interview in the television series’ Episode 4.

Her surname "Chitose" combines the characters for "thousand" (千) and "year" (歳). A trivia note reveals her name was listed as 'Chiharu Yuzuka' in the 2015 short film, though she dismisses this as a false name.