Souta Mouri, a student with hidden fetishes, is relentlessly bullied by the sadistic Student Council President, Maina McMuffin. However, the power dynamic shifts dramatically when Souta discovers a mysterious glowing notebook that turns his written fantasies into reality. By documenting his desires, Souta transforms the haughty Maina and her loyal assistant, Shino, into submissive servants who crave his domination.
Using the supernatural power of the M-Note, Souta transforms the sadistic Student Council President, Maina, into his devoted masochistic slave. Although Maina initially attempts to maintain her haughty attitude, she quickly succumbs to Souta's commands and finds intense pleasure in her new role. The situation becomes further complicated when Shino, the president's assistant, reveals that she is also Souta's slave, sparking a competitive rivalry between the two women for their master's affection.
Maina and Shino enter a fierce competition to determine who is the most devoted masochistic slave for their master, Souta. As both girls vie for his exclusive attention through increasingly daring acts of submission, Maina finds herself feeling insecure about Shino's domestic skills and unwavering loyalty. Caught between two eager subordinates, Souta struggles to make a choice, fueling a rivalry that pushes both women to their limits.
As Maina and Shino compete for Souta's favor as his devoted masochist slaves, Souta delivers a surprising verdict to resolve their rivalry. Rather than choosing between them, he orders Maina to claim Shino as her own subordinate slave, establishing a new hierarchy of submission. Now bound by this command, the two women continue to serve Souta together, blending their competitive rivalry with a shared, erotic devotion to their master.