Peko comes off as a very serious and stern woman who shows little to no emotions. She speaks with an authoritative tone of voice, and she is mostly business. Despite her authoritative tone, she is respectful of authority figures and does not police the other students. She also loses track of time when practicing martial arts, but she is not antisocial or unwilling to stay around the other students, as can be seen when she agrees to attend the Ultimate Imposter's party in Chapter 1.

In her first Free-Time Events, Peko reveals that she has a strong affinity for animals, though they themselves do not share the same feeling. She stated that because of her choosing the path as a frightening warrior, all animals couldn't stand her menacing aura and always ran from her before she could have the chance to touch them. One of her favorites that mentioned in one of her Free Time Events is a Panda, as she is looking forward to touch them someday.

It also revealed that she was not able to smile because she thought she never really needed to smile. Over time, because she completely neglected it, she eventually forgot how to smile. She wants to make her childhood friend (which is highly implied to be Fuyuhiko) to smile again, so she has a strong motivation to able herself to smile. Mahiru also notices that Peko was the only one who never smiled in her taken photos, and afterwards Hiyoko Saionji taught her how to smile "in her way". She is somewhat very oblivious to the "smile" emotion, engulfing all of Hiyoko's childish and evil "How to smile guide" mentioned in one of her Free Time Events.