Mikako Satsukitane presides as student council president at Sorami Academy, acting as an upperclassman to Tomoki Sakurai and Sohara Mitsuki. Her family leads a yakuza organization, bestowing immense wealth and influence that provides access to weaponry ranging from firearms to tanks and warplanes. This heritage fuels her readiness to bankroll extravagant, often dangerous schemes, tournaments, and festivals for her friends. She exhibits high intelligence and academic excellence yet consistently fails moral education, necessitating supplementary lessons. Mikako blends refined elegance with manipulative cunning and overt sadism, frequently targeting Tomoki for humiliating pranks or perverted incentives purely for her own amusement. Despite this cruelty, she demonstrates genuine concern, emotionally supporting Ikaros or funding group activities.

Physically, Mikako possesses long purple hair tied with side ribbons, narrow dark-purple eyes, and a tall, curvaceous figure standing 164 cm (5'4.5") with measurements of 83-56-80. She typically wears the Sorami Academy uniform and maintains a characteristic sadistic grin. Her abilities include exceptional combat prowess matching Eishiro Sugata and a grip strength of 400 kg noted by Nymph. She exhibits extraordinary luck, striking gold or oil through random digging. Technical aptitude enables her to modify Angeloid programming, granting Oregano speech. Mysterious connections to Synapse appear across media: manga chapters imply non-human origins when Sugata questions her "real birthday," while the movie *Eternal My Master* depicts her with angelic wings rewriting Ikaros' data and appearing in Synapse-associated flashbacks.

Her core dynamic involves childhood friend Eishiro Sugata; she uses "Ei-kun" privately and displays intense jealousy, once shooting him over misunderstandings involving the angel Charon. She treats Tomoki as a plaything yet includes him in group protection efforts. With Angeloids, she blends mentorship and manipulation, training Astraea in violence while offering guidance or employing Oregano as a maid/assistant. In spin-offs like *Daisuki Desu!! Mahou Tenshi Cosmos*, she appears at age 18 punishing Sugata for perceived infidelity. The manga *Yūryō Bukken Mō Dame Sō* features her at age 25 intervening in conflicts involving Sugata's brother. Mikako's birthday is November 10, and she experiences recurring conflict-themed dreams. Her family's appropriation of national budget funds earns them the nickname "Black Money."