Monodam is a child-like robot. Unlike his overly talkative siblings, he is very quiet. For the most part, he doesn't speak even to his fellow siblings, and he is somewhat of an outcast in the group. He sometimes appears a bit shy and seems to be blushing. When he does talk, Monodam speaks in a typical monotone robotic manner, making him appear very emotionless and thus unpredictable. He tends to silently stare at others, with no visible reaction when others speak to him. He occasionally speaks short sentences unexpectedly in a rather loud voice, which may startle others due to his usual silence. The rare moments when he laughs sounds especially unnatural due to his very robotic voice. All of this causes him to come across rather creepy, much more so than his siblings. Like all the Kubs, Monodam imitates Monokuma by constantly calling the students "you bastards". Despite appearing very unresponsive, it's later shown that he seems to act more independent than the other Kubs. It appears that he is the most intelligent out of the Kubs, as he is capable of staying calm and make logical arguments when the other Kubs were too scared and confused to do so, and even when he knew barely anything about what is going on.

Monodam speaks in a stereotypical robot voice, very monotone and robotic. This voice should be in the medium high to medium to even medium low range for a male.