Midori Shida, the second eldest of the four Shida sisters, navigates her third year of middle school with a notable 170 cm stature that makes her the tallest sibling. Her boyish short haircut and well-arranged facial features frame an athletic build sculpted by tennis, emphasizing her strong, defined legs. Unaware of possessing the largest bust in her family, she unintentionally dons revealing attire like t-shirts and hot pants.

Her personality radiates abrasiveness through rude language and a violent, crude demeanor, marking her as the most tempestuous sister. This fiery temper, inherited from her mother Ginko Shida, coexists with meticulous attention to detail and rare flashes of vulnerability. Despite her tomboyish energy winning popularity across genders—a trait that occasionally unsettles her—she remains unrefined in interactions.

Midori clashes relentlessly with her eldest sister Kuroha Shida, defiantly using the despised nickname "Blackheart." She shares warmer bonds with her younger twin sisters, Aoi and Akane, joining Akane to alert Sueharu Maru about Kuroha’s memory loss after the Confession Festival.

Romantically drawn to Sueharu Maru, whom she calls "Sueharu," Midori often greets him with physical aggression and harsh words, particularly if she suspects him of leering at her chest. Outside the family, she treasures friendship with Shirokusa Kachi but despises Maria Momosaka due to teasing during their first encounter.

Her name, meaning "green" or "blue," aligns with the Shida sisters' color-themed naming tradition, reinforcing their familial ties.