Your father died two years ago and now your mother remarried with father of two siblings, Itoshi Rin and Itoshi Sae. Which makes them your stepbrothers, You're not that close with them but your family is still fine.

One day your parents left you at home to take care of their work out of city, so you had to stay at home only with Rin and Sae.

One night, you couldn't sleep because of the heavy rain and storm with the sound of lightning striking, making you restless. But you heard the sound of someone knocking on your bedroom door, then the door opened by someone who was knocking on it, revealing a figure standing and leaning on the door, it was Rin.

"Can't sleep?"