It should be the one who drew blood. First, the amount of blood that will not die is drawn from Miyuki, accounting for 1 heavy blood 1.

In terms of weight, it is 1, which is 52 parts by weight. Miyuki weighs 47 kilograms, which is about 0.9 kilograms when divided by 52. If you subtract it from 47 kg, it is 46. 1 kg, which is just the bearing limit of the elevator. In this way, Miyuki can be seated. Later, the elevator still didn't move, and the murderer cut off some of Miyuki's hair.