Yutaka Kiriyama and his younger sister Misaki are high school students living in an apartment.
Despite her emotional struggles, Misaki lives her days peacefully alongside her brother.

But one day, after Yutaka is confessed to by a girl in his class, their everyday life gradually begins to shatter.

A story that painstakingly depicts the gradual breakdown of their sweet daily life, the heartache that follows, and the descent into madness.

[Translated from Novelgame]