Living alone is the first step toward becoming an adult. At 18, young people head to Tokyo, each carrying their own hopes and dreams. With support from their parents, they find the joy of having their own small private space—a feeling that remains nostalgic and deeply memorable for many. This personal living space also becomes the starting point for romance and intimate relationships. A one-room apartment turns into a private bedroom for sex, free from interruptions. Reliving personal experiences through various scenarios brings back memories, fuels fantasy, and naturally builds excitement. Sex in a comfortable room becomes a special moment, marking one's first step into adulthood.