Infection: The Chain of Lust ~Yu Yamagishi Arc~

Story

The protagonist, Yasuyuki Kato, a second-year at 'Private Suzugamine Academy,' has a crush on Yu Yamagishi from another class. He even joined the 'Film Research Club' that she belongs to, aiming for her, but he still hadn't been able to convey his feelings. Amid all this, the members of the 'Film Research Club' plan a two-day, one-night training camp during this summer vacation. On the first day of the camp, in the school's audio-visual room, the members notice that something is off about Shindo. Her eyes are vacant, and her speech is gradually growing slurred. The club advisor presses her chest as if hugging her own shoulders with both arms, and begins trembling in small shudders. She rushes out of the audio-visual room. After the film viewing, Takeuchi, who secretly holds feelings for Shindo, goes to fetch the teacher himself, and stops in his tracks just before the infirmary upon hearing a woman's lewd moans. On the bed, Shindo is kneading her own exposed breasts with her right hand, legs spread wide, her left hand toying with the fully visible bulge at the center. Her eyes glow an eerie red. At that moment, something terrible was unfolding outside the school. A mysterious virus that had suddenly emerged, 'UNKNOWN level4,' was spreading throughout the town. It was said that once infected, one becomes dominated by intense lust and attacks the opposite sex according to their desires...