How does it feel to be alone…?
Aren’t humans supposed to be social beings…?
Why does everything feel so distant…?
That day was a cold rainy nightfall…
The voids behind me and the endless darkness ahead…
All I can see is just a single thread of ‘light’…

Aourth, a mirror of Earth. Everything is stagnated. Suzu who preserves those dear to her and Shizu who struggles for a better school life. The twin witnesses the ‘light’ both at day and night. Throughout the countless threads, one binds to a girl, Murazuki Shizu…

Unlike the usual isekai fantasy we thought of, this is the true reality. A world woven by the sins of its origin. There’s no stopping him, yet a thread of ‘light’.

His sins under the twilight are brought to an end by the emotion once lost…