Sayori is initially portrayed as the character archetype of a Genki Girl, expressing a bubbly and cheery disposition. She is very clumsy, noted for finding ways to accidentally hurt herself or to drop random things. Regardless, she is shown to be a jokingly cunning individual who can trick others to get food. Sayori is also known to obsess over activities that she loses interest in later. She states that writing poetry and studying literature is different to her than those other interests because it helps her explore her feelings.

Later, however, it is revealed that she suffers from bad depression and works so hard to make the people around her happy to cope with her own lack of self-love amongst other things. She is also usually the only character, other than the protagonist, shown to break up arguments, Monika noting that her sentiments are necessary to keep a relaxing atmosphere in the Literature Club.

Sayori is also introduced as the protagonist's childhood friend. The protagonist seems to view her as an airhead and slightly annoying at the beginning of the game, but he starts to sympathize with her after she confesses about her depression.