Ryoko Toba is the younger sister of Minami Toba. She grew up camping often with her family, as her father loved outdoor activities, and she continued to enjoy camping as a hobby into adulthood. She commonly camps alongside her sister, and the two share a close sibling bond built around their mutual love for the outdoors. Ryoko has a practical and down-to-earth personality. When she first appears at a campsite, she helps Rin Shima light charcoal, demonstrating her hands-on camping experience. She also lends her Nissan Lafesta to Minami for the Izu camping trip, showing her generosity and willingness to support her sister. Despite her calm and helpful demeanor, she can be straightforward and firm when necessary; for instance, she worries about Minami drinking beer during lunchtime and does not accept non-alcoholic beer as a substitute, insisting it is still unacceptable. The members of the Outdoor Activities Club initially mistake her for a boy due to her appearance, but this does not affect her interactions with them. Her role in the story is that of a supporting character who reinforces the theme of camping as a family and shared activity. She does not undergo significant personal development on screen, but her consistent presence alongside Minami highlights the importance of trusted companionship in outdoor adventures. Her notable abilities include practical camping skills such as fire-building and lending logistical support through her vehicle, as well as a level-headed sense of responsibility that balances her sister's more relaxed approach.