Kaori

 This page mentions suicidal topics, which may be distressing to some readers. Kaori (香織) was Ryosuke Takahashi's love interest and the arranged fiancé of Rin Hojo, before her untimely death.

History
Kaori was Rin Hojo's arranged fiancé due to her family's business relationships. However, Kaori ended up falling for Ryosuke Takahashi and was determined to pursue a relationship with him despite her father's disapproval. In response, Rin verbally abuses her out of frustration, claiming her family will suffer as a result. In the end, Kaori commits suicide leaving both Ryosuke and Rin heartbroken with the latter becoming murderously vengeful against Ryosuke.

Ryosuke Takahashi
Ryosuke was Kaori's only love interest at her college. He cared about her even when she revealed the fact that she may be forced into an arranged marriage by her parents. Her final phone call was to Ryosuke to say goodbye before she committed suicide. She was the one who gave Ryosuke the inspiration to start Project D.

Rin Hojo
Rin Hojo was Kaori's fiancé and her senior. He loved Kaori even though she didn't have the same feelings for him. When Rin found out Kaori was in love with someone else and didn't plan to marry him, he tried to blackmail her by telling he will create troubles for her father's business and job. Due to all these pressures, she committed suicide.

Father
Kaori's father raised her in all luxury and paid for her college. When he found out she did not want to marry Rin, whose family his company owned success to, he was angry at and forced her to marry him. His actions led to his daughter's demise.

Trivia

 * Kaori is based on Aya Kiguchi (木口 亜矢, Kiguchi Aya), a Japanese model.
 * Kaori's theme is a rendition of the Franz Schubert composition Ellens dritter Gesang, commonly known as Ave Maria.
 * She is the only character in the series to die.