Doki Doki Literature Club! The Original Game Voice Dubbed

She always has a calm, gentle expression and is portrayed as mature and hard-working.

Despite Monika's upbeat attitude in the Literature Club, it becomes increasingly obvious that she is actually sad and lonely, as a result of being aware that her whole world is just a simulation; a simulation in which she can't even achieve what is considered "happiness" (i.e. having her route completed). She is fixated on obtaining the love of player because they're the only "real" thing in her life. Monika's actions are also motivated by her desire to escape the torture she endures whenever someone quits the game, as when that happens Monika is trapped in a hellish void of noise, lights, colors, and screams, unable to move or even think. This is mentioned during Monika's Talk in Act 3. 

Sayori is initially portrayed as the 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 things. Regardless, she is shown to be a jokingly cunning individual who can trick others to get food, shown after managing to eat Natsuki's cookie without her permission. Sayori has also been known to obsess over an activity, only to drop it a few days later, as stated by the protagonist during an interaction between them. This could also be the case with writing poetry, as the protagonist wonders if she might drop it later on, though he also notices that she is a lot more passionate about writing, as she mentions earlier on that it helps her to express and understand her feelings better.

However, it is later 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 (proven by her absence in Act 2). Monika notes that while she may look like a good leader, Sayori is usually better when it comes to dealing with people, notably at mediations. 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.

Yuri is portrayed throughout the majority of the game as being shy, generous, polite, apologetic, very intelligent, mature, eloquent, and passionate about topics she is interested in, although she is also very insecure, awkward, and has a tendency to act slightly condescending and patronizing to mask her self-doubt. Her facade of passivity and level-headed nature occasionally breaks, however, as Yuri does argue passionately and aggressively with Natsuki over their differing opinions on writing styles. Yuri has a deep desire to be liked by others and is afraid to speak her mind on matters as she believes it will make her seem unlikable. Due to her social ineptitude, she can be innocently insensitive, but once she realizes what she said could be considered rude, she almost immediately apologizes, repeatedly saying she did not mean it. As stated by the protagonist, Yuri likes to think before she says something.

Yuri is the "shrinking violet" (a term to describe a character who prefers to blend in with the scenery than to attract unwanted attention) or "dandere" of the club members because of her constant apologetic nature. The attribution is also because of being shy to discussions beyond her category of interest, her interests being literature, horror, and general surrealism, which she examines and articulates expertly and encourages others to follow as well. In the middle of Act 1, Natsuki and Yuri getting into a debate about their different writing styles. Choosing to side with Natsuki will cause Yuri to shy away from the player, and if the protagonist attempts to read their poem to Yuri, she will not respond, which will cause the protagonist to decide it is best to leave her alone. If the player calls for Sayori to diffuse the situation, Sayori will compliment both Yuri and Natsuki on their writing and capabilities. The argument will dissolve afterwards and both Yuri and Natsuki will be satisfied with Sayori's response.

Yuri's love of surrealism seems to be foreshadowing further events of the game, with Yuri's surrealistic eyes and the game's horrific nature after Sayori's suicide. Yuri prefers poetry that uses metaphorical symbolism and enjoys collecting unusual ornate knives, implicitly (in Act 1 at least) used for self-harm. The detailed summaries of the Portrait of Markov novel in the first and second act, when also taking the scattered dialogue references into account, all end up tracing back to her unstable nature and unhinged personality.

During Act 2, Monika amplifies Yuri's negative personality traits. This causes her to have sanity slippages that result in an abnormal obsession with the protagonist and her already-existing hobbies becoming more of perverted detailing and self-destruction, to the point where Monika suggests that Yuri cuts herself due to a fetish. This also causes her to become invasive and condescending to the other club members, asking Natsuki "Why don't you look for coins under the vending machine?", which causes Natsuki to cry and run away. In one occasion, Yuri shows a poem to the protagonist with blood and urine stains on it, telling him that she has put her scent on it. Yuri will then realize what she has done and leave the club, stating that she is going to vomit.

Yuri recognizes that something is wrong with her and that her comments and behavior are inappropriate, enough so to feel something bad will happen despite her happiness. She is ultimately unable to control her obsessive outbursts. It reaches a point where, after she confesses her love to the protagonist, she stabs herself to death out of over-excitement or rejection (depending on the protagonist's response to her confession, both lead to the same outcome, courtesy of Monika). Yuri's body is left decomposing for three days, and is then discovered by Natsuki, who immediately vomits and runs away. When she is discovered by Monika, both Yuri and Natsuki's files are deleted, leading to Act 3.

The protagonist is one of the five main characters, one of the five members of the Literature Club, and the only playable character in Doki Doki Literature Club!. The protagonist uses whatever name the player gives him, but he is a separate entity from the player.

In Act 2, after the first few lines and the game script gets rewritten, the protagonist will have no memories of the events that happened in Act 1, acting as though Sayori never existed. In Act 4, he will have no memories of the events that happened in all of Acts 1, 2, and 3.

The protagonist was designed to function like a typical visual novel protagonist. He acts blunt and mean towards Sayori, his childhood friend; teases Natsuki, the tsundere; is warm to Yuri, the shy girl; and falters around Monika, the popular girl. According to Dan Salvato, he is deliberately given very little focus.[2]

More specifically, the protagonist is an underachiever, preferring to play video games and watch anime instead of applying himself and having friends. Despite this, when he does interact with others, he tries to be kind and thoughtful. He takes note of how people around him are acting and feeling, although more subtle things may go over his head. He is shown to be clever and observant in Act 1.

He tries his best to help even when he is out of his depth, as seen when he tries to ease Sayori's depression, despite not understanding it.

He shows a distaste towards those who are judgmental, shown by a scene in Natsuki's route, and in Yuri's route, he is accepting of Yuri's interest in knives, highlighting an open-minded personality.

The protagonist is true to his word and always attempts to keep his promises; he works harder if he knows people are counting on him.

Although the protagonist's primary interests are self-oriented, he does show a liking towards "cute girls", deciding to join the Literature Club on the basis of cute girls attending.