Izumi Isozaki is two years younger than the other characters and shares many similarities with Itsuki Akiba. However, she's far less reserved about her feelings, particularly her love for Ichitaka Seto. In fact, she openly declares her affection to nearly everyone she encounters. Izumi is also more adventurous and holds a number of superstitions related to love. She frequently follows Seto around, and on multiple occasions, has attempted to seduce him into intimate situations as a way to demonstrate her devotion.
She remains persistent in her pursuit of Seto's affections, insisting that she will do anything necessary to win his heart. Izumi first appears midway through the manga, meeting Seto at the beach during their summer vacation, later learning they attend the same school. Her attraction to Seto begins after he defends her from an overly aggressive boyfriend, leading her to manipulate him into going on various dates throughout the series. Convinced that he is her soulmate, Izumi is determined to make Seto her boyfriend.
