Seta Kaoru is a second-year student at Haneoka Girls' High School and the guitarist of Hello, Happy World!. She is very popular with ladies, whom she dubs her "little kittens". Uehara Himari and Ushigome Rimi in particular have a tendency of blushing in her presence.
Outside of the band, she is also Shirasagi Chisato's childhood friend.
Kaoru is a tall girl with angular facial features, slanted crimson eyes and long purple hair worn in a ponytail. She has chest length forelocks and bangs that frame her face with a single lock that hangs loose between her eyes.
Her casual attire is normally boyish and formal.
A flamboyant actress, Kaoru has an extravagant personality. She is rather pretentious and bombastic, having a tendency to use impressive sounding words to the point of sounding foreign and hard to understand. She sees herself as a prince, and sees other girls as the princess while quoting Shakespeare (sometimes incorrectly). She appears highly flirtatious, and is very popular among other girls, not only for her passionate mannerisms, but because she is also surprisingly reliable. If she is aware someone may be in a bad mood or feels sad, she will try to encourage them or help them feel better.
When by herself, her "quirks" seem to lessen, if not vanish entirely at times. She appears to be aware of how she can come off to others; sometimes she struggles to have time to herself due to having so many fans, and is aware that she likes certain things that don't fit her "character". She is even able to increase her actress personality if she feels it is necessary.
Though she appears very intelligent, she can often be just as air-headed as Kokoro and Hagumi. Her catchphrase is "fleeting" - though when Hagumi questioned her about what it meant, Kaoru could not answer.
A list of characters Kaoru interacts with in the game.
- The normal art for Kaoru's initial 3★ card, She Who Colors The World, depicts the scene where she accepts Kokoro's invitation to join her band.
- Kaoru's theatrical, princely, and flirty personality is a rather open parody of the anime otokoyaku, that is, the anime and manga heroines, inspired by playing male characters actresses from the all-female Takarazuka Theater. It is also emphasized by her close friendship with the very feminine Chisato, who can be compared to musumeyaku, actresses who perform female roles in the same theater.
- Kaoru used to call Chisato "Chi-chan" when they were younger and is actually really embarrassed about that.
- In return, Chisato calls her "Kao-chan". Kaoru gets flustered whenever Chisato calls her by that nickname.
- She's also in her high school drama club with Yamato Maya.
- She is both the tallest member of Hello, Happy World! and tallest of all the 25 girls.
- Kaoru is scared of both heights and scary things, the former said by herself and shown in GARUPA☆PICO Episode 6 as well, while the latter proven in the The Cursed Well and the School's Ghost event.
- Kaoru hides what she truly likes and tells people what she thinks sounds cool.