Naoko.

Naoko meets Yusuke while staying on an island for medical treatment. Yusuke's graceful athletic figure captivates her eyes and she falls in love with him. But their relationship is soon broken after Yusuke's father dies while trying to save Naoko from drowning. The memory of Yusuke leads Naoko to the track, and six years later, they meet each other again at a Marathon competition. Naoko decides to become a manager to help Yusuke, a gifted runner, and they embark on training together to heal their sorrows from the past.