Orihime is a teenager of average height. She has brown eyes and long, waist-length, burnt orange hair. Her most noticeable physical trait is her slender yet curvaceous figure for a teenager, especially in terms of her large breasts. She wears her hair in bangs tucked behind her ears with hairpins, which she only removes to sleep, as they are worn in the memory of her brother. Orihime initially wears her hair with a full but parted fringe before pulling most of her bangs behind her ears as she was ready to leave for Soul Society, a change noted by Tatsuki.
Seventeen months after Aizen's defeat, Orihime's hair becomes fuller and wavier. Her bangs naturally frame her face without her hair clips and also hang over her ears. She stops wearing her hair clips and instead keeps them clipped onto the left collar of her school uniform.
Orihime is independent, friendly, humorous, sensitive, caring and kind. She comes off as naive and rather clueless, which is at odds with her exceptionally high marks in school. She studies hard because when her grades drop, she receives less financial support from her relatives. She is a member of the Handicrafts Club and likes to invent very ridiculous sports to play with Tatsuki (such as "base-cer," a combination of baseball and soccer). She tends to zone out with her mouth open and loses track of what she was thinking or dreaming about. She has an over-active imagination and gets carried away thinking of implausible scenarios, such as portraying herself as a futuristic and highly destructive robot in an assignment asking a student "How do you see yourself in the future?".
Orihime likes Asian flower print clothing and comedies. While she does eat some normal food, Orihime cooks and eats unusual meals, which other people often find unappetizing. Her favorite food is red bean paste and she likes putting butter on sweet potatoes. She enjoys cheese and butter most of the time.
Orihime has demonstrated that she is perceptive when it comes to people's mental and emotional state, especially in regards to Ichigo, as she is able to tell what kind of driving force is pushing someone. She additionally has a crush on Ichigo and later falls in love with him. She has exhibited traits that appear to have some connection with Ichigo, such as the ability to detect Ichigo by scent, sense his Spiritual Pressure even when masked by the Visored, and an awareness of what mood Ichigo is in, sensing his feelings of anguish, disappointment, or worry, even feeling pain herself when she sees Ichigo getting hurt.
Orihime and her brother, Sora Inoue, were raised by a drunken father and a prostitute mother, who always argued and beat their children. Fearing that their parents would kill Orihime, in the March that Sora turned eighteen, he ran away with Orihime, who was three years old, and raised her on his own from then on. For nine years, Orihime and Sora lived in harmony despite the fact that Orihime was bullied in school because of her unusual hair color. One day, Sora gave Orihime a pair of hairpins. However, Orihime refused to wear them because she said they were childish. That day, Sora died, and Orihime began wearing the hairpins every day since. After Sora's death, Orihime prayed for him every day. A year after Sora died, Orihime met Tatsuki and befriended her and the amount of days she prayed for him diminished. After entering Karakura High School, she stopped praying for him and instead talked about Ichigo before she left and when she returned from school. She wanted to show Sora that she was happy and that he did not have to worry about her.
Since Sora's death, Orihime has lived by herself in Karakura Town, receiving financial support from a distantly related aunt living elsewhere.