Otome Kayashima is a third-year student at Seiou Academy in the anime Girl Friend Beta and a member of the Japanese Culture Research Association. She is tall and slender, with distinctive mint-green hair and dark aubergine-colored eyes, and she is generally regarded as beautiful. In person, however, her demeanor is defined by laziness, unfriendliness, and unsociability, and she tends to appear dull and listless. This detached real-life manner contrasts sharply with her online presence, where she is highly active on social networking services and keeps many friends. She posts every day, typically sharing photographs of her homemade character bento lunch boxes and T-shirts bearing strange or cheesy slogans, often the sort of whimsical souvenir-shop shirts with faintly ridiculous writing.

Otome has an eccentric, pop-oriented personality with a strong attachment to cute things. She enjoys making decorative character bento and collecting various cute character goods, and her lunch boxes are elaborately decorated, though the taste of the food itself is only average. Her sense of what counts as cute leans toward the quirky, and she has a habit of dressing in casual, slogan-covered T-shirts rather than more polished outfits. She only wears properly coordinated clothing when a holiday or school event forces her to, and she has mentioned that the school is fond of having students change clothes for various occasions.

Within the story, Otome functions as a supporting figure among the many students whose everyday school life forms the backdrop of the series. Her motivation centers on maintaining a comfortable distance from face-to-face socializing while enjoying the connection, attention, and friendship she cultivates online. Her key relationships reflect this split: although she appears unfriendly and distant in person, she holds a lively social circle through social media, where her quirky posts attract a steady audience. Her notable abilities lie in her bento-making craft, her knack for producing and curating amusing content online, and her enthusiasm for collecting cute character merchandise, all of which align naturally with her activities in the Japanese Culture Research Association. Her development is understated, as she remains defined throughout by the contrast between her muted school persona and her energetic, sociable online identity, with her eccentric hobbies bridging the two sides of her character.