Blue Drop: Tenshi-tachi no Gikyoku  

BD, Blue Drop, Синя крапля - драма ангелів, Синяя капля: Драма ангелов, BLUE DROP ～天使達の戯曲～, Blue Drop: Tenshitachi no Gikyoku

Five years ago, there was an event on Kamioki Island that caused great distress and resulted in the death of all humans except for one person, Mari Wakatakes. This traumatic experience erased all memories from her mind. Now, against her will, she is enrolled at a secluded girls' academy where she remains oblivious to the fact that others are watching her, waiting for her memory to resurface. Deep within her subconscious lies the most terrifying secret: while Mari was the only human survivor, she may not have been the sole survivor of the event on Kamioki Island. As a strange girl with whom she is inexplicably drawn yet cannot trust approaches Kaihou Academy, Maris only hope for survival might lie in this enigmatic figure.