Mana harbors a secret sexual desire she can't tell anyone. She fantasizes about defecating and urinating in the classroom while masturbating. Just imagining herself pooping in an empty classroom after school, feeling the tension of someone possibly walking in, makes her aroused. This urge gradually consumes her thoughts. Eventually, she actually defecates in the classroom after school. Her heart pounds so hard she feels it might leap out of her throat, yet the unprecedented sensation leaves her mind completely blank. Enthralled by this feeling, she gets carried away and even administers an enema. Mana can no longer resist this impulse—it's become utterly uncontrollable.