All through Middle School, Natsukawa Aika's family were in a tough spot due to her father's career change. As such she had no time for relationships, and didn't even understand them. So when Sajou Wataru asked her out, she rejected him. However he kept clinging to her, never giving up. At some point, he woke up to reality. He realized that she was someone he could never be with, and decided to keep his distance from her, so as to not bother her anymore.
However, when he started doing that, Natsukawa felt a gap in her life. Like something was missing. She realised that she'd gotten used to his presence and wished for them to stay involved with one another.
With the help of her friend Ashida, and over a period of time, Sajou understood her desire, and decided to hang out with her again, while maintaining a certain distance.
From Natsukawa's point of view, she was becoming increasing conscious of Sajou. Always wanting to walk home together, wanting to meet up over summer break, feeling bad whenever he spoke to other girls, etc.
During the Cultural Festival, Sajou helped resolve an issue for the executive committee, bringing to an end a nightmare of endless work for its members. One of which was Natsukawa Aika.
Natsukawa felt that it was uncharacteristic of Sajou to do this. So she decided to ask him why he'd gone to such lengths, to which he replied, "love bring about weakness".
After such an eventful festival, Natsukawa started realizing her true feelings. She suddenly started noticing little things about Sajou that she'd never noticed before. She was paying extra attention to every little detail about this boy, who she'd rejected many times in the past. On their way home after her realization, she couldn't hold herself back and hugged him from behind, pretending that she'd tripped. She started wondering whether he still liked her.
In the previous volume (V8), Shinonome Claudine Marika planned to hurt Sajou Kaede (Wataru's Big Sis) out of jealousy, as the latter was close to student council president Yuki (Shinonome's fiancé). She calls her to the student council office and plans to meet her there with a pair of scissors in hand.
By a stroke of luck, Sajou Wataru ends up going in his sister's stead. Shinonome panics and falls into despair, making a sudden choice to end her life. To snap her out of it, Wataru stabs his palm, showing Shinonome his blood.
The volume ends with President Yuki telling Shinonome to give up on their arranged marriage, and with Sajou going back to class with an injured left hand. He tells everyone in class that his injury was an accident, the result of his clumsiness.