21-year-old doujinshi artist Rin Nanase has an unexpectedly voluptuous figure despite her youthful, girlish face, and remains a pure maiden who has only ever kissed a man. Traveling from Hokkaido to Tokyo, she wonders whether this city will bring her the angel of love or the demon of desire—setting out to uncover the truth. Shocked by her first sight of an erect penis, she feels a mix of embarrassment and confusion at the dense patch of pubic hair peeking from beneath her underwear. Here lies her first crossroads—and the moment she will lose her virginity.