Tsutomu Kariya is a high-achieving high school student with a perfectly respectable academic record and a secret hobby he keeps to himself: browsing erotic hidden accounts on social media. Among the many anonymous posters he follows, one stands above the rest—a user who goes by the handle RIKA. He regards her as something close to a goddess, and the provocative photos she posts have become a private source of comfort in his otherwise disciplined daily routine. One day, Tsutomu happens to witness a confrontation in the staff room between a teacher and Matsurika Tachibana, the undisputed idol of his class. Matsurika is beautiful, popular, and the winner of the previous year's school beauty pageant. Spotting her in distress, Tsutomu steps in to help, and in the process, he notices several small details that align perfectly with the RIKA account he worships. He blurts out a half-joking question, only to have Matsurika confirm the truth: the perfect angel of the classroom and the bold, exhibitionist RIKA are the same person. Rather than panic, Matsurika seizes the moment. She proposes a mutual arrangement: they keep each other's secrets. Tsutomu will never reveal her hidden account, and in return, she will allow him a front-row seat to the side of herself that no one else sees. What begins as a transactional pact quickly evolves into something stranger and more intimate. The two discover that their personalities, both privately sly and secretly lecherous in matching ways, fit together uncannily well. On screen, Matsurika is daring and risque; face to face, she acts demure and proper. Forced into close contact by their shared secret, Tsutomu and Matsurika navigate a relationship that blurs the line between pure romance and openly mutual desire, all while keeping up appearances at school. As volumes progress, the story deepens beyond the initial premise. Tsutomu and Matsurika learn about each other's troubled family backgrounds and begin to fill an emotional void neither had fully acknowledged. They eventually become an official couple, but the path is not entirely smooth. A new complication arrives in the form of Tsutomu's beautiful younger stepsister, Mizuki, who enters their shared apartment with her own agenda and forces the new lovers to navigate jealousy, family dynamics, and the awkwardness of introducing a romantic partner to a skeptical sibling. The supporting cast includes Tsutomu's only real friend at school, Shiro Amakusa, a flashy, easygoing extrovert who initially seems like an unlikely confidant but proves to be surprisingly perceptive and loyal. The narrative arc traces Tsutomu and Matsurika's journey from secret-sharers to genuine partners, exploring how two people who each wear a mask—one the diligent grind, the other the school idol—learn to trust each other with their truest, least presentable selves.