Heads

This manga's story is based on a thriller by Keigo Higashino. The main protagonist, the shy Jun Naruse, is a rather average guy who works for a electronic company and loves to draw. He falls in love with Megumi whom he met at a shop selling drawing materials and an intimate relationship develops. A few days later the office gets attacked and when the criminal tries to shoot a little girl he saves her by jumping in front of her.A month passes until he wakes up again and is told that half his brain got destroyed and he only survived because someone donated half a brain. Everything seems to be fine, he quickly recovers and is happy, however he begins to change...is the donated brain the reason for that? Or is it just a side effect of the medicine?