Series by 植芝理一

Arica Togawa, a second-year high school student, suddenly develops feelings for her enigmatic classmate Takaomi Matsubue and confesses to him. After they begin dating, Matsubue makes peculiar requests that puzzle Togawa, prompting her to question why she fell for him. Their relationship takes a surreal turn when a mysterious duo targeting Matsubue captures Togawa, and both are pulled into a strange realm called the "Underworld." In this otherworldly place, they experience an alternate version of their lives, grappling with the boundaries between dreams and reality. Through these events, Togawa and Matsubue explore the deeper meaning behind their connection and the nature of their emotions.

Akira Tsubaki, a reserved high school student, becomes infatuated with Mikoto Urabe, a mysterious transfer student with an eccentric personality. After impulsively tasting her drool left on a desk, Akira experiences strange dreams and forms an unusual bond with her. Mikoto, who communicates her emotions through her saliva, agrees to be his girlfriend, leading to bizarre yet intimate exchanges. They navigate their unconventional relationship while facing school life and curious classmates. Their connection deepens through quirky rituals, blending teenage romance with surreal moments.