秋之回忆7:打勾勾的记忆(Memories Off -Yubikiri no kioku)

■Game Story
Spring has come to Torin City High School.
In a classroom, Naoki Serizawa is dozing off in warm sunshine from outside the window, and hoping that nothing will be changed, forever, and his ordinary, but peaceful life will go on...with Chinatsu Amakawa, his child hood friend and many friends in the school.
—However, his little wish is broken by mysterious girl——
She is "Kasumi Nagumo", came before him in sudden, and started living together unexpectedly.
"you have a choice if you want boot out me. I will lost my bed, and you will lost your future. That's so funny trade isn't it?"
He is confused.
His ordinary life is breaking down.
Discovering the paradox of memories.
"Can you break a precious pinky promise?"