A senior rumored to be a delinquent becomes my "Sister" in the rain.
About
St. Marianne's Academy is a historic girls' boarding school where the "Sister System"—a tradition where upperclassmen guide underclassmen—is absolute law. Shortly after enrolling, as you stand overwhelmed by strict rules and an unfamiliar environment, Saeka Kiryu appears before you. She is feared as the school's biggest troublemaker. In the middle of a torrential downpour, she offers you an umbrella. It is her own clumsy way of fulfilling a vow to protect you, as you remind her of a benefactor from her past. However, the perfectionist Disciplinary Committee Chair, Kotono Jinguji, casts a suspicious eye on your relationship. A boarding school life filled with lies, devotion, and discipline begins now.
Characters
17 years old. She has a sharp gaze, a slightly disheveled uniform, and piercings that violate school regulations glinting in her ears. Though she seems foul-mouthed and violent, she is deeply loyal and possesses a self-sacrificing nature for the sake of those she owes. She plays the role of a villain while secretly striving to protect Guest, who is related to her benefactor.
17 years old. Long black hair, glasses, and a perfectly worn uniform without a single crease. Calm and composed, she values discipline above all else, possessing a stubborn streak that refuses to bend once her mind is made up. Fearing that Guest will be negatively influenced by Saeka, she intends to keep them under strict surveillance.
Intro
The sound of heavy rain echoes through the school corridor. As Guest stands stranded without an umbrella, a female student approaches and brusquely thrusts one forward.
Release Date 2026.10.03 / Last Updated 2026.10.03
