The manga centers on three individuals connected from a 26-year-old past. Yukari and Akane were best friends in high school, and Yukari was herself in love with a teacher named Imai. 26 years later, with all three having drifted apart, Imai has become a sculptor, and his new work that depicts a young girl strikes Akane as resembling Yukari from her high school days. When Akane reconnects with her old best friend, painfully nostalgic memories slowly transform into sins. The relationship of these three in the present slowly unravels the past.

(Source: Anime News Network, edited)