Peko Pekoyama is a character in Danganronpa 2: Goodbye Despair, and her title is the Ultimate Swordswoman. Peko has a serious and mostly emotionless demeanor, not emoting when interacting with other people and exhibiting an intimidating aura. Despite that, she isn’t an entirely anti-social person either - as she was alright with attending the party in chapter 1 despite being uneasy in crowded spaces and had felt bad she couldn't assist with figuring out the power outage because she was feeling unwell. So even though she has a pretty intimidating exterior and stoic personality, she truly means no harm and does want to help with whatever she can. As it turns out, she doesn’t mean to act cold. During her free-time events, she revealed she never felt the need to smile during her childhood and essentially forgot how to “properly” smile on command and wants to be able to do that for her childhood friend (who is heavily implied and possibly canonically Fuyuhiko). As it turns out, she’s Fuyuhiko’s right-hand lady and “bodyguard,” but wasn’t revealed until Peko killed Mahiru in chapter 2. As it turns out, because of how the Fuyuhiko clan raised her, she believes herself to be a “tool” and less than human, her only purpose is to serve what Fuyuhiko wants. However, because Fuyuhiko doesn’t want to rely on his family’s power, Peko has the feeling that he hates her since she’s essentially the personification of that reliance (even though it's far from that), and further fuels her desire to make him happy (hence why she murdered Mahiru - so she would take the fall and blame of it so he wouldn’t do so himself).

Though she tries to hide it, Peko has an extremely kind heart - especially for Fuyuhiko and her classmates. Though they can be frightened of her, she deeply loves animals - especially fluffy ones. So though she was the culprit in her murder, she still felt hurt and remorseful for both killing her and needing to lie/betray everyone, wishing they’d not bend to the killing game again like she had. She also is always willing to soften up her cold exterior and stand by her classmates, such as assisting Akane and Nekomaru with taking down Monokuma, and splitting open a coconut for Ibuki, Hajime, Teruteru, and Souda, glad she can be of use and can enjoy themselves because of her. However, her deepest desire is to protect Fuyuhiko - not as a tool, but as his right-hand lady and as his best friend.

As a remnant, she stood alongside Fuyuhiko Peko’s side and murdered countless people during the tragedy - in the final episode of the Despair Arc, the two stood back to back amongst many slaughtered bodies of the Japanese Diet, very much implying they were the culprits. Peko served as Fuyuhiko’s right-hand, serving out his orders and attacking whoever gets in his way. When a few of the Future Foundation members attempt to capture him, she dashes in and protects Fuyuhiko with her swordsmanship skills, and fights in his honor - alongside classmates and remnants Nekomaru and Akane.

Honestly, I think each of Peko’s voices fit her in their own different ways, so any of these interpretations work well with me! Whatever you think fits Peko!

Voice Comparison: https://www.youtube.com/watch?v=EoZiEWa7Xrc 

Voices for Reference (ENG): https://www.youtube.com/watch?v=UEF7_ZHIuGY 

Voices for Reference (ENG Anime): https://www.youtube.com/watch?v=8E__jn82WnI 

Voices for Reference (JPN): https://www.youtube.com/watch?v=IcX-nuKALYg