After losing her parents in a traffic accident, Tsubasa relied solely on her older brother for support. Though deeply scarred emotionally, she maintained a pure and gentle heart, treating everyone—even the strangest individuals—with kindness. One day, while she was birdwatching at a park, an older man approached her and forcibly invited her to his house. Initially flipping through a bird guidebook, the man's behavior soon turned bizarre and unsettling. This story explores how Tsubasa's innocence affects even the most dire circumstances, depicting her inner strength and the transformation of those around her.