One quiet night, Akira Moriya is unexpectedly drawn into the Spirit Market, a surreal realm of drifting lights and strange whispers. Amid its dreamlike haze, he encounters Tsukiko Kamimine, a wounded girl whose presence feels both fragile and otherworldly.

Helping her escape the realm marks the beginning of an unforeseen bond—and the faint stirrings of the SigilBound System, a mysterious interface that awakens within Akira’s sight.