Noah, the daughter of the Eikawa family, is an innocent girl who suddenly lost her memory one day. As a result, she has no memory of anything prior to Noah days. Shiori, a maid, is by her side as her caretaker. The two of them are the same age and quickly become close, trusting each other to the point of having sex, and eventually Noah comes to dote on Shiori. However, the two share a past that they can never erase. Before she lost her memory, Noah had sexually assaulted Shiori...