Mikuru Katsuhara, nicknamed "Micchon" by friends and called "Mi-tan" by Akira Takizawa, is a 21-year-old Japanese woman with brown hair and brown eyes. Her distinctive outfit typically includes a white shirt with blue sleeves featuring the word "earth," dark blue or purple jean shorts, dark pink tights or stockings, and white boots, often completed by a pink hair clip and occasionally a blue coat.

She is shy and reserved around strangers but becomes more open and frank with close acquaintances. Mikuru frequently displays boredom or emotional detachment, though she is easily flustered. She exhibits significant attachment to her personal laptop, handling it with extreme care and rarely allowing others to use it.

Professionally, Mikuru works as a computer programmer for the "Eden of the East" group. She holds the critical role of developing and maintaining their core asset: advanced image recognition software capable of identifying individuals from photographs and retrieving their online information, making her a trusted and indispensable team member. Her exceptional programming skills earn mutual respect from fellow tech specialist Yutaka "Panties" Itazu due to their complementary abilities.

Within the group, Mikuru maintains a close friendship with Saki Morimi and is Kazuomi Hirasawa's cousin. Her interactions with Itazu involve underlying personal tension; she frequently reacts with anger toward him for unspecified reasons, which other characters interpret as potential romantic interest. Throughout narrative events, including those in *Paradise Lost*, her role remains consistently focused on technical support and system maintenance, avoiding direct involvement in the Seleção conflicts. Her surname "Katsuhara" derives from the Japanese words for "arrowroot" (葛, katsu) and "field" or "plain" (原, hara).