In this act, the player writes poems for Sayori, Yuri, or Natsuki. The player talks to each of them and spend time with his/her chosen lover; Sayori usually likes the player's poems regardless of who the player wrote them for, but comments later that she knows the player wrote them for Natsuki or Yuri. While she tries to hide her sorrow, it is apparent that losing the player's attention bothers Sayori. If one checks the game files, he/she will notice that Monika puts files or documents in the game files after he/she has written every single poem, regardless of for whom it was written.
Sayori will be the only person who confesses to the player in Act 1. While rejecting her confession results in heartbreak, accepting her confession does not alter the path of the game, save for a few lines of dialogue and a CG. Despite the fact that on the surface the game does not appear to have been altered yet, Sayori's personality has seen a fundamental change over the course of Act 1, from a happy, bubbly personality to a more melancholy, bittersweet one (and from depressed to all-out suicidal in the span of just a few days), in which Monika's tampering with her depression is heavily implied (and later explicitly stated) to have played a part. Act 1 will end when the player sees Sayori's body hanging in her room.
If the player chooses to write for Natsuki, the second day will have them find her searching for her manga in the classroom closet. The player will then proceed to spend the club time with her, reading the manga, Parfait Girls, which Natsuki particularly likes. The player will receive a CG of them reading the manga.
Once the time to share poems arrives, Monika, Sayori, and Yuri comment on the likeness to Natsuki's writing style, whereas Natsuki is flustered and dismisses the player's poem as merely "okay," showing traits typical of the tsundere type to which she is likened.
If the player chooses to write for Yuri, the second day will entail reading a book which she had bought for them (although she denies doing this), which shows a CG of reading beside each other from the same book. The player makes comments on how the book's protagonist reminds him of Yuri, to which Yuri becomes extremely embarrassed.
When sharing the player's poem with Yuri, she is taken aback but provides constructive feedback for the player to consider and use to improve their writing style. Natsuki, on the other hand, dislikes the poem but still offers constructive feedback.
If the player chooses to write for Sayori, the second day will allow the main character to fall asleep, then be woken up by Sayori. The player will comment that Sayori takes better care of him than she does for herself and points out some flaws in Sayori's appearance, which leads to a CG of the main character buttoning up Sayori's blazer.
Writing a poem for Sayori has the most different reactions between the four girls. When sharing the player's poem with Sayori, she states that she likes it a lot and when the player reads her poem, he mocks her for writing hers on the day itself. Natsuki simply states that his poem is "ok", though it did not evoke any emotion from her, and Yuri remarks that it is the player's first time writing, just like how if he were to write for Natsuki.
After sharing the player's poem with all four girls, the player notices Yuri and Natsuki in the process of sharing theirs. Natsuki remarks that Yuri's poem is "fancy", to which Yuri responds by saying hers is "cute", offending Natsuki. The two then argue about their own writing styles, eventually leading to Natsuki accusing Yuri of trying to impress the protagonist. Insulted, Yuri tells Natsuki that she's just jealous, but Natsuki only responds by telling Yuri to stop being full of herself. The argument eventually evolves into a full-fledged fight, with Yuri mocking Natsuki for being cute and Natsuki accusing Yuri of padding her bra. The player then has to decide on what to respond.
If the player agrees with Natsuki, Natsuki becomes proud and happily accepts the player's opinion, only for the player to chide her when Yuri becomes upset. Natsuki then reluctantly apologizes to Yuri.
If the player agrees with Yuri, he tells her that Natsuki's writing style should not be ridiculed and Yuri apologizes. The player than tells Natsuki that she took it way too far, only for Natsuki to refute, saying that Yuri started the argument. Monika steps in, reminding Natsuki that Yuri already apologized, prompting her to do the same, but Natsuki, clearly angry with the lack of support for her, leaves the room.
If the player instead asks Sayori for help, Sayori will go on to praise both girls for their own writing styles, but also accidentally causes more awkwardness, causing Yuri and Natsuki to both become embarrassed. The player than praises Sayori in front of Monika.
On day three, Monika is found to have moved all of Natsuki's manga up to the top shelf, and Natsuki is forced to find a way to reach them. This awards the player with a CG as the player holds onto the chair while Natsuki grabs the box of manga, in a position where the protagonist can almost see up her skirt. Once she has the box, she asks the protagonist to take it, but she changes her mind as she looks down and thinks that the player is perving her out. Her anger in this situation causes her to fall, and she lands on top of the protagonist, accidentally causing him to crease a page in one of the manga. She cries when she fails to remove the crease and the player decides to help her clear up her mess and cheer her up, causing her to tell him that he's being really nice to her, which is not a usual thing for her to say, confusing the protagonist.
When sharing poems, Natsuki is even more flustered than on day one, struggling to admit that she really likes his poem. Yuri becomes apologetic, stating that her argument with Natsuki the previous day only caused the player to dislike her. Yuri then tells the player to hang out with Sayori or Natsuki instead and the player does not get to read her poem.
On the third day, Yuri and the protagonist continue where they left off in the book from the second day. Yuri requests to sit against the wall on the floor, rather than at the desks, due to her frequent back pain. The protagonist suggests this is due to her bad reading posture, which Yuri goes along with in embarrassment. Yuri goes to get tea with the player, but Monika interjects, stating it is a one-man thing, to which Yuri coldly responds that it is none of her business. Once outside, Yuri immediately regrets saying that and the player reassures her. Yuri notes that the player is being very nice to her and states that she likes being friends with him. When they get back, Yuri expresses how she can't hold chocolate while holding her book, prompting the protagonist to feed her them, earning the player a CG in the process. When the player does feed her chocolate, Yuri gets embarrassed, but Monika interrupts them before anything else can happen.
When sharing poems, Yuri is even more impressed with the player's poems, noting all the different techniques the player used and can use. Natsuki states that the poem is better than the first, but she still does not like it.
On day three, Sayori asks the protagonist to help her find supplies for the posters that she and Monika plan to make for the festival. She explains what is planned for the event as they search for an empty classroom, and demonstrates a poetry performance. When they find a room, Sayori immediately finds a box of crayons, then drops one. While she bends over to pick it up, she smacks her head on the shelf. The protagonist suggests that he find something cold to put on her head, which rewards the player with a CG of Sayori holding a bottle of apple juice to her head.
When sharing poems, Sayori remarks that she is once again impressed and that she loves reading them. The player then admits that he is able to write his poems better because he keeps thinking of Sayori, which causes her to react in shock.
On day four, when the player enters the clubroom, he notices Sayori staring blankly at her desk. When he asks her what's wrong, Sayori hurriedly dismisses him, causing him to worry. He first asks Monika about her, but Monika says that she doesn't see anything off with her, but she goes over to talk to her anyway.
When Natsuki approaches the protagonist about reading her manga, he asks her about Sayori as well, causing her to appear jealous and a bit angry. However, after going into more detail, Natsuki calms down and reassures the player that since Sayori is his best friend, if she did have problems, she would bring that up to the player himself.
When sharing poems, Natsuki seems to finally admit that she really likes the player's poems, even comparing him to her own skills. Natsuki then begs the player to tell her that she is a good writer. When the player asks for her poem, Natsuki becomes very apprehensive and does not show it to him, claiming that it is a bad poem, but she finally gives in and hands it to the player. It is revealed that her poem is actually about the player himself, which is why she was nervous about handing it over. When the player tries to return it, Natsuki declines shyly, saying that she does not want it.
Again, the player is unable to read Yuri's poem as she feels that he prefers Natsuki over her. Sayori notes how the player wrote his poem for Natsuki and is clearly upset by something, but before the player can say anything, she leaves the classroom early, claiming she is tired.
After Monika goes over to talk to Sayori, the player notices Yuri staring at him from behind her book. When he asks her about Sayori, Yuri states that she also noticed Sayori's weird behavior and tells the player that Sayori could be harboring feelings for him and that Sayori is very lucky to have someone like him care about her.
When sharing poems, Yuri praises the player for his improvement in writing. She then has a heart to heart talk with the player about her love for books and the characters inside them, as well as how she is unable to talk to people due to her low self-esteem. She also tells the player that all these feelings were removed because of the player treating her like everybody else. Unlike Natsuki, she is extremely eager to show her poem, but like Natsuki's, it is a tribute to the player. When the player finishes her poem, she becomes extremely flustered and looks away, but the player reassures her that he likes it. Like Natsuki, when the player hands her back her poem, she returns it to him, asking him to keep it.
The player is unable to read Natsuki's poem, as she angrily refuses to read his, clearly annoyed by the player writing more like Yuri. Sayori again reacts as she did if the player pursues Natsuki.
When sharing poems, Sayori states that it is the player's best poem so far, but the player again asks her whats wrong, only for Sayori to start tearing up and asking the player why he chose not to befriend the other girls.The player claims that he and Sayori have a wavelength, but Sayori only gets sadder, saying how it would be easier on her if the player instead talked to the other girls. When the player gets worried, Sayori quickly dismisses the conversation and heads home.
After sharing poems and Sayori leaving the clubroom, Monika starts her preparations or the festival by handing out duties to each of her members; she will be printing pamphlets to promote the club, Sayori will be helping her design them, Natsuki will be baking cupcakes and Yuri will be creating banners to set the atmosphere for the clubroom, leaving the player to decide on who to help.
If the player chooses to help Monika, Natsuki and Yuri immediately disagree and tell Monika that her job requires the least amount of work; furthermore, Sayori is already helping her. Monika defends herself, stating that the player clearly chose her, but Natsuki accuses her of scaring him into picking her and Yuri claims that she chose the player for ulterior motives. This causes Monika to further defend herself, rebutting that the two of them also have ulterior motives. Natsuki and Yuri then tell Monika to be more responsible, saying that being alone would lower the standards of their work and that the club's resource should be fairly divided. Monika finally gives in, but even though she agrees with them, she is clearly upset that she is unable to spend any time with the player.
The same thing happens if the player picks Sayori. Natsuki and Yuri again state that Sayori and Monika would be working together, therefore she would require the least amount of help.
If the player picks Natsuki, she becomes extremely happy, despite her not wanting any help in the first place. Yuri becomes passive aggressive, stating that she is used to working alone. Natsuki then notices Yuri once again being upset and starts praising Yuri for her talent in an attempt to cheer her up, which surprises everyone in the club. The player then exchanges phone numbers with her.
If the player picks Yuri, she is taken aback and becomes flustered again. Natsuki claims to not care about the player's decision, but everyone knows that she is actually really unhappy about it. Yuri then tries to cheer Natsuki up, praising her talent in baking, which appears to work. The player then exchanges phone numbers with Yuri.