Soshite, Mina ni natta

In broad daylight, a horrific mass murder occurs, claiming the life of Mina, a high school student. Miraculously, she survives through a heart transplant. As Mina begins to settle back into a semblance of normalcy, she becomes alarmed by an overwhelming surge of murderous intent that she's never experienced before. Unbeknownst to her, the heart she received belonged to Misako Shimizu, the very perpetrator of the mass murder. Mina's parents watch in confusion and fear as their beloved daughter starts transforming into a person they can no longer recognize. The murderous urge only grows stronger and seems unstoppable. Witness the beginning of an unprecedented family suspense drama! (Source: Bookwalker)