Sayori is one of the four main girls and the protagonist's childhood friend and also a member of the Literature Club. She's also the club's Vice-President in Act 1 until she was replaced by Yuri in Act 2 after she was deleted by Monika. She appeared in Act 1 and Act 4 of Doki Doki Literature Club. In Act 4, she becomes the club's President in Monika's absence after being deleted in Act 3. She is one of the three girls you can write poems for.
Sayori has coral pink hair, cut short in a slightly messy bob, with a red bow on the left side of her head. Her eyes are sky blue, and she is of average height and weight. She wears the normal school uniform like the other members of the Literature Club, though unlike the others, Sayori keeps her blazer unbuttoned, and her collar is crooked.
When playing through her route, Sayori wears a pink shirt and blue shorts.
Sayori is portrayed as a talkative person, being very bubbly and kind and the archetype of a Genki Girl. She is very clumsy and notorious for finding ways to accidentally hurt herself or to drop things. She is usually the only character, other than the protagonist, capable of breaking up arguments, and is described as being paramount to keeping a relaxing atmosphere in the Literature Club. Sayori tries her best to help everyone be happy and dislikes attention directed at her well-being because she feels unworthy of anything that others have to offer her.
Sayori's depression makes her disorganised, and often she "cannot find a reason to get out of bed in the morning"; her room is untidy, and we are told the protagonist often used to clean her room for her. The protagonist notes how there hasn't been much change in her, and only later the protagonist notices changes is Sayori is due to Monika's interference, amplifying her depression and suicidal tendencies. Her relationship with the protagonist and other people's happiness are her main coping mechanisms since she believes that if she makes everyone else happy, she will not have a reason whatsoever to be unhappy.
This list does not include 1X1 roleplays to keep them from getting disrupted.
All information (except appearances) is taken from here.