Kouichi was walking home one rainy day with his imouto Meguri under the same umbrella when he suddenly heard a loud thud behind him. It was not the rain, but the sound of something heavy falling from above. Even though he sensed that he shouldn’t look back, his curiosity got the better of him. What he saw was his osananajimi Reina, with a pool of blood spreading out from her body.
Reina remained in critical condition over the next few days, with no sign of waking up. Was it a suicide or murder attempt, or simply an accident? Kouichi and Meguri fretted over their childhood friend’s sudden predicament. However, Reina then suddenly appeared in front of them, even though she should still be sleeping in the hospital. She had returned as an apparition, with no recollection of the day of the incident. If they could recover her memories, then she might regain her consciousness. The three of them search for the cause of Reina’s fall, as their feelings entangle like a spider’s web.