Chizuru Mizuhara

The main heroine of the series. She is enrolled in the Faculty of Literature at Nerima University. She is one year younger than Kazuya, at 19 years old. Her birthday is April 19th. She is 162.5 cm tall and hails from Tokyo. She graduated from Asukayama North High School and lives in Room 204 of Royal Hills Nerima.

She is a rental girlfriend affiliated with the rental girlfriend agency Diamond. She holds the record for being the most popular in the Fresh Class, with all her reviews being five stars (perfect score). Later, she is promoted to the Regular Class. "Chizuru Mizuhara" is her name as a rental girlfriend, while "Chizuru Ichinose" is her real name.

Due to Kazuya introducing her as his real girlfriend to his friends and family, she reluctantly goes along with the lie. She changes her clothing and demeanor between her rental girlfriend persona and her private life, keeping her rental girlfriend job a secret at university.

She met Kazuya through the rental girlfriend service, and later it was revealed that they are neighbors. Initially, she kept her distance from Kazuya as a client, but later she redefined their relationship as "fair neighbors" and began interacting with him privately as well.

In reality, she is an aspiring actress, and the money she earns from being a rental girlfriend is used to pay for acting school. Her reason for pursuing acting is a promise she made to her late grandfather, and she wants to show her ailing grandmother, Sayuri, her movie debut.

When Sayuri's condition worsened and her movie debut seemed impossible, Kazuya suggested the idea of a crowdfunded independent film. Subsequently, she began working with Kazuya as a business partner. During the film production, she hesitated when Umi invited her on what was essentially a date, but with Kazuya's encouragement, she decided to go to seek support for the crowdfunding. When parting ways, Umi asked if she liked Kazuya, to which she confessed that she didn't dislike him, but she didn't exactly like him either.

Right after the film was completed, Sayuri's condition suddenly changed, and Chizuru prepared for the worst. Kazuya questioned whether it was right to keep lying to Sayuri about having a fake boyfriend, causing Chizuru to struggle. However, miraculously, Sayuri regained consciousness and advised Chizuru on the meaning of both truth and lies, and the importance of continuing to think about them. Tearfully, Chizuru expressed her feelings to Sayuri, but ultimately did not reveal her rental girlfriend job.

After the funeral, Kazuya rented her for a day and offered her heartfelt encouragement. During their final meeting at the park, her emotions for her late grandmother overflowed, and she cried in Kazuya's arms.

During a trip to Hawaiians, Mami exposed her rental girlfriend job to her family. Doubts arose about her relationship with Kazuya from Kibe and others, but thanks to her quick actions, the suspicions were cleared, and the fake relationship was maintained.