Takeuchi is a somewhat crazy person, often thinking of new experiments to do in order to further his studies. This is evident when Kurusu asks if they will be dead after getting shot to which Takeuchi's response is by shooting Yamagami multiple times. During the moment when Moriyama gets bitten, Maeda proceeds to kill him in order to put him out of his suffering. Takeuchi comments that Moriyama would have made a "valuable sample", implying that he would've used him for experiments and such.