Ran Gotanda (五反田 蘭, Gotanda Ran) is Dan's younger sister and is currently attending Saint Marianne Academy, an all-girls middle school. She is currently a 3rd year and the Student Council President.
She has long scarlet hair that goes down to her hips and tied up in a rough ponytail. She has a very slender body that with loose clothing, making her curves more pronounced. At home, she normally wears a loose top and shorts that aren't zipped fully. But if Ichika Orimura is around, she immediately changes into a loose white dress.
In the light novel, she apparently thought of dying her hair black when she was younger as she was conscious of Ichika.
Although Ran often argues with her brother, she is a kind person that cares about her relatives. She often worries about little details relating to Ichika, as she wants to gain his attention.
- Dan Gotanda - Her older brother; both of them tend to argue often.
- Ichika Orimura - A friend of Dan. She has a crush on him but, because she's not in the IS Academy like the other girls, she can only meet him occasionally. Because of that, she has decided to take the entrance exam for the IS Academy in order to be with him.
- Houki Shinonono - The 1st childhood friend of Ichika. Ran feels she is a rival. She met her in Volume 4 (anime OVA). When they both met, she felt at a disadvantage to Houki for her bust size and that she is way prettier than herself.
- Lingyin Huang - The 2nd childhood friend of Ichika. She and Ran competed in getting Ichika's attention through cooking (Japanese vs Chinese, furthermore they both are from families who own restaurants where Ichika often goes to eat).
- Charlotte Dunois - Classmate of Ichika in Class One and IS Representative Candidate of France. Ran first met her in Volume 6. Both saw each other as love rivals with different advantages (Ran's younger age and hair color vs. Charlotte's actress figure and motherly like character).
She is introduced to the story by barging into Dan's room to announce lunch time when he was playing video games with Ichika. While Ran initially wore loose-fitting and revealing clothes, she got nervous around seeing Ichika quickly adjusted her clothes. Later on when Ichika and Dan were eating, she changed into a white dress and told Ichika to make himself at home. Ichika noticed her change of clothes and asked her if she were going out somewhere, which she hesitated, so he asked if she was on a date in which she denied.
In a shopping mall, Ichika runs into Dan and Ran shopping. When Dan tells him that the tons of bags he's holding were Ran's swimsuits and that she planned to showing them to Ichika, Ran kicked him away before he could finish, surprising Ichika. She then tells him that next year she'll join the IS Academy and become his underclassman. Ichika wishes her good luck and tells her to study for her exams. While Ran looks for Dan, Charlotte appears and pulls Ichika away to a swimsuit store and they get into the changing room. Dan arrives and asked Ran: "Where did Ichika go?"
"The last summer at Middle School is special! Pool-use swimsuit! Beach-use swimsuit! 'It's on!' swimsuit! Ultra 'It's on!' swimsuit! Mega-ultra 'It's on!' swimsuit! You need each kind to use as the situation calls for!"
- Ran's name in kanji means "orchid" (ran, 蘭). Her name matches her hair color.
- Ran's hairstyle with a bandana resembles the Final Fantasy's Rikku character.
- In the light novel, she had a fan club consisting of middle-aged men.
- Ran shares similarities with Kallen from Code Geass, sporting the same hairstyle and personality.