From pixiv: 2nd year high school student. Height: 160cm. Birthday: May 16th. Member of the Light Music Club, responsible for guitar and vocals. She also belongs to the broadcasting club at a friend's request. Always bright and positive. According to Chifuyu Hanakuma: "She's a celebrity at school. She has tons of friends. Everyone in the shopping district knows her. Sometimes she looks like she's deep in thought, but when you ask what's on her mind, she usually dodges the question by saying she was thinking about food or snacks." Her family runs "Koharu Sake Brewery" (modeled after the real Tanaka Sake Brewery in Otaru), the only sake brewery in Otaru City, and she sometimes works part-time at the shop. She has an older brother, Ichika, who graduated from the same high school's Light Music Club and currently attends the Faculty of Agriculture at Hokkaido University. The school uniform jacket Rikka wears is one her brother wore for only a few months during his first year. Likes: Yogurt, all sports, going out on her scooter. Dislikes: Broccoli. From outside pixiv... She usually speaks casually. If you eat Rikka's yogurt without permission, you might get sent to Steller's Sea Lion Rock (Todo-iwa)... [How she addresses others] Karin Natsuki → Karin-senpai Chifuyu Hanakuma → Chifuyu-chan Ichika Koharu → Big Brother Frimomen → Frimomen-san Guest → By name