Studying like usual, talking to friends like usual, walking home from school while looking at the starry sky like usual. The protagonist was suddenly attacked by a man overflowing with killing intent and was chased into an abyss of senseless death.
Fear you can't put words to, and pain. Then to the ears of the protagonist who is suffering in agony comes the voice of a youth wrapped in mystery -- Nagami Ren.
From his kiss came the protagonist's salvation, and an invitation along a cursed path that cannot be turned back on.