About
The story
Five years before becoming the Nakano family's teacher, Futaro met a young girl in Kyoto whose photograph he treasured. When a young woman dressed in white reappears before him and introduces herself as Rena, he thinks he's reunited with the friend who had encouraged him to change. However, she takes the photograph back and asks him to forget their promise, transforming this encounter by the lake into a new enigma.
Rena is not a sixth sister: this identity is first assumed by Itsuki at the request of Yotsuba, the real girl Futaro once met. Itsuki borrows their deceased mother's name to free Futaro from a memory that Yotsuba considers too burdensome. She then uses this disguise herself to try to reveal the truth to him, making Rena the symbolic face of the secret that connects their past to the present.
