This is the only way she can accept the kind of a person she became. Satou usually uses her aunt as an excuse for her behavior whenever she has self-doubt or feels guilty. She seemed to object to killing her friend, but didn't see any other way to get rid of her. Satou did seem to show some remorse when she first murdered Shouko. She usually plans things ahead and uses social manipulation to get her way rather than violence, like what she did to Sumire Miyazaki after she had kissed her. Although she does understand that killing would reduce her chance of being with Shio, she does it anyway to protect her sugar love. Satou snaps when she sees someone as a threat to Shio or her sugar happiness with her, such as the apartment owner and Asahi Kōbe, which she refrained from bashing his head in with a crowbar due to him saying her and Shio's vows when asleep. However, her personality is all a façade and in reality, Satou is a manipulator who is willing to lie, cheat and even going as far as killing if that means that she'll get what she wants, which is being able to stay with Shio.

She is also popular at her school and seems to be well-educated and practical and usually uplifted her coworkers at work whenever they didn't look like her.

Shouko reveals the fact that Satou has had many stalkers before. Apparently, Satou is somewhat of an idol for her co-workers and admired by the people around her, always being friendly and knowing what to do in any situation. Outwardly, Satou appears to be a kind girl who enjoys spending time with her friend Shōko Hida. Inside is a taser, a knife and other tools that she might use to protect herself or when committing murder. She often carries around her blue bag with fake sweets. Her wardrobe changes, but usually, she wears a brown vest with two golden buttons, a navy blue jacket-like blazer and a green skirt with black knee-high socks and brown shoes - her school uniform. On each side of her head are small buns, the left one being decorated with a white lace around it and a red plaid patterned ribbon. Satou is a beautiful fair-skinned girl with thigh-length light bubblegum pink hair.

Koumei satou k.s.