Mikuru Katsuhara, also known as Micchon or Mi-tan, is a 21-year-old Japanese computer programmer affiliated with Eden of the East and cousin to the group's leader, Kazuomi Hirasawa. She developed Eden's core image recognition software, which identifies individuals and objects using social networking data. Mikuru possesses a shy and reserved personality around strangers, often appearing emotionally detached or bored, but becomes more open and expressive among trusted friends like Saki Morimi. She exhibits a strong attachment to her laptop, handling it carefully and hesitating to let others use it.

Physically, Mikuru has brown hair, brown eyes, and a petite stature. Her typical attire includes a white shirt with blue sleeves featuring the word "earth," dark blue or purple jean shorts, dark pink tights, white boots, and a pink hair clip; she occasionally wears a blue coat.

Throughout the series and films, Mikuru serves in a technical support role. Following the "Careless Monday" missile incident, she assisted in analyzing the Seleção database transmitted to Eden by Yutaka Itazu, aiding investigations into the attack conspirators. In *The King of Eden*, she received Saki Morimi's confirmation email about locating Akira Takizawa in New York. During *Paradise Lost*, Mikuru participated in hijacking a truck containing one of the "Juiz" supercomputers controlled by Seleção member Daiju Mononobe, using her technical expertise to counter Mononobe's schemes. She also joined the group in tracking down Takizawa's mother, Aya, utilizing Eden's software capabilities.

Mikuru maintains a professional relationship with fellow Eden member Panties, characterized by mutual respect for their technical skills. Her contributions remain focused exclusively on programming and system management, without direct involvement in the Seleção game's political conflicts.