Two people live next to each other in a desolated housing complex where people have less communication than before... They had been separated apart by a wall, but now they are getting very close to each other thanks to a key! A life in a housing complex, syrupy-sultry-lovey-dovey-chu-chu with a blond-haired girl next door! A blue-eyed blond girl, Alice Terada. Her mother's treatment is close to the child neglect. She is alone in her school, frequently bullied by classmates due to her peculiar hair and eyes. She can feel tranquility only when together with "Oniichan" next door, who always gives her kind greetings with affectionate smiles. Usually, she kind of hesitates to chat with him. But one day, when she lost the key and is at a loss before the door, "Oniichan" helps her. This event triggers further events! Alice's body and mind have long been locked in the loneliness... Who will open?