Frustrated by her gossipy classmates, Natsumi seeks solace in the most remote restroom, only to discover the enigmatic Arisugawa-san has transformed a stall into a lavish hideaway. As Natsumi delves deeper into Arisugawa-san's world, she finds herself drifting from her peers. Meanwhile, behind Arisugawa-san's regal facade lies a web of intricate secrets.