Act 1 is the first section of the game.
As of update 1.1.0, it is possible to trigger an abnormal story event at the very beginning of the game. At the start of the very first scene, the game will check to see if monika.chr is intact. If not, then Sayori will immediately appear, express confusion and panic, and then the "END" screen will show for several seconds, after which an audio loop of static will play while a monochromatic image of Sayori hanged is onscreen. At this point, all of the files in the character folder are deleted. This screen will persist even if the game is restarted. After ten minutes, the text “Now everyone can be happy.” will fade in on the right side of the screen over the course of another minute, written in Sayori’s handwriting.
This event is unlikely to be triggered by a normal playthrough of the game because all character files are replaced when a new game is started for the first time. This means that a player must start a new game, quit or return to the main menu, delete monika.chr, and then start another new game to see the event. It’s unknown what the significance of this event is.
At the beginning of Act 1, while the player is on his way to school and meets Sayori who explains that she overslept but managed to make it just in time to meet the player. The two discuss what club the player will join, and although the player claims to have no memory of agreeing to join a club, Sayori reminds him that he did. She explains that she worries that he will become a NEET if he fails to join one.
Eventually, the school day ends, and the two meet up. Sayori encourages him to join the school's literature club, of which she is the vice president. The player tells her that he is going to the anime club instead, but Sayori explains to the character that she promised the club a new member and that Natsuki made cupcakes. He apprehensively agrees to go, to Sayori's delight.
Sayori brings him upstairs, an area which the player explains he does not visit very often due to its primary usage being for third-year students at the school. The two enter the room, and the player is introduced to Yuri, Natsuki, and Monika, respectively. Sayori explains that Natsuki is the energetic one and Yuri is the smart one. The player and Monika have already met prior to the club, and the player says that Monika and him shared a class the year before, where she was the most popular girl in the class, since she was smart, beautiful, and athletic.
Natsuki goes to get her cupcakes while Yuri fetches some tea. Natsuki's cupcakes are decorated like cats and while Yuri talks to the player about tea, Monika interrupts her to tell the player that Yuri's just trying to impress him. Monika tells the player that although she was on the debate club the year before, she left due to the "politics" involved in major clubs, and decided to start her own club. The player reveals that he has not read much in the past few years other than manga.
After welcoming his return, Sayori reveals that Yuri has brought a book for him. After this, an exclusive scene will play depending on whom the poem the player wrote appealed to.
If the poem appeals to Sayori, he will slump at a desk and listen to Sayori and Monika discuss the upcoming festival. After that, Sayori comes over. The main character berates Sayori for how messily she dresses before trying in vain to button up her blazer.
If the poem appeals to Natsuki, he will go up to her as she looks for manga. They briefly discuss the topic before sitting down to read Parfait Girls. While reading, Natsuki vents on how people judge her for reading manga.
If the poem appeals to Yuri, he will read his new book Portrait of Markov with her. The two will also talk about Yuri's tendency to ramble and second-guess herself.
After the event, the main character shares his poem with the other club members. The others will respond based on how the poem appeals to them.
Once this is done, the girls will share poems with each other. Natsuki and Yuri will argue over their writing styles, leaving the main character to choose who to agree with. Alternatively, the main character can ask Sayori to help dissolve the argument.
As the protagonist walks in, Sayori attempts to ask him to go buy a snack together. He refuses, saying that it's a ruse so that he'll have to buy it for her. Yuri and Natsuki join in on the conversation, the latter giving Sayori a cookie. Monika then rushes in, apologizing for being late because she was practicing piano. She promises that she'll play for them once she gets better.
At this point, another exclusive scene will play depending on whom the player's previous poem appeals to.
If the poem appeals to Sayori, she will ask the player to follow her as she gets supplies. A box of crayons eventually hit her head and the main character consoles her with a bottle of apple juice.
If the poem appeals to Natsuki, she will take the main character to the closet, where she reorganizes her manga. She will fall and land on the main character.
If the poem appeals to Yuri, she asks the player to help her get water to make tea after which they read together. Yuri becomes flustered after the main character gives her chocolate.
After listening to all the poem responses, Monika will announce that they will be doing a poetry performance. After being apprehensive, Natsuki and Yuri will agree. Everyone will then recite a poem.
On the walk home from school, Sayori will ask, if given the chance, whether or not, they'd walk home with whomever their poems have most appealed to (if the poem appeals Sayori, then she defaults to Yuri). The choice the player makes has no bearing on the progression game.
Though no abnormal events happen until Chapter 5, a small out-of-place interaction occurs while the club members discuss the upcoming festival.
MONIKA: "Squid...?" "That's a pretty specific thing to look forward to..." NATSUKI: "Oh, come on." "Are you saying you don't like squid?" "You, of all people?" MONIKA: "Eh? I didn't say I don't like it." "Besides, what do you mean by 'you of all people'?" NATSUKI: "Because!" "It's right in your name!" "Mon-ika!" MONIKA: "Eh?!" "That's not how you say my name at all!" "Also, that joke makes no sense in translation!" NATSUKI: "...?" MONIKA: "Ah...never mind!"
This interaction is the first hint that Monika knows about the nature of her existence. Natsuki's joke is a play on Monika's name and the Japanese word for squid (Japanese: 烏賊, Hepburn: ika); this is the only mention of Japanese remaining in the game, as version 1.1.0 removed a reference Yuri made to "kanji," replacing it with "words." Monika notes that Natsuki's pronunciation is incorrect, as ika would typically be pronounced with an emphasis on the final syllable in typical Japanese, while Monika's name would be pronounced with an emphasis on the first syllable. Japanese, though no more strictly a tonal language than English, similarly has situations in which homophones could be confused if intonation is ignored.
The first abnormal event in typical story progression occurs near the end of this act after the player is given the choice to confess his love for Sayori or not. Regardless of which is chosen, the file hxppy thxughts.png is written to the game folder.
Act 1 ends with the player character walking into Sayori’s room, finding her hanged from the ceiling in an apparent suicide. Eerie music plays (Sayo-nara) and the screen distorts heavily, a technique not used prior to this moment but very common from this point on. The background temporarily changes into an error message, referencing a file called traceback.txt where errors are logged. In the characters folder, sayori.chr is deleted. traceback.txt, abridged, reads as follows:
I'm sorry, but an uncaught exception occurred. While running game code: File "game/script.rpy", line 67, in script call File "game/script-ch5.rpy", line 289, in script File "renpy/common/00start.rpy", line 260, in <module> renpy.call_in_new_context("_main_menu") JumpException: Oh jeez...I didn't break anything, did I? Hold on a sec, I can probably fix this...I think... Actually, you know what? This would probably be a lot easier if I just deleted her. She's the one who's making this so difficult. Ahaha! Well, here goes nothing.
This file is a genuine error produced by Ren'Py, but the game manually invokes it with the message which is shown. If the game encounters an actual error, then this file will be overwritten.
The game fades to black, and the word "END" is shown on screen for several seconds, after which the player is returned to the title screen.
The title screen is changed from Act 1; Sayori is no longer present. In her place is a corrupted mess, consisting of tiles from the other three characters on the screen.
Additionally, the "New Game" text is replaced with predetermined glitch text (ŔŗñĮ¼»ŧþŀ Żŕěōì«). Save files from Act 1 are intact, but attempting to load them will first yield a fake error message citing the absence of sayori.chr, then load Act 2. Pressing "New Game" will also load Act 2.
It should be noted that witnessing Sayori's suicide is considered a point of no return in-game. Once the player enters Sayori's room, any attempts to load a save file to an earlier point in time will prompt the game to immediately start Act 2.
Another abnormal event has a chance to take place while in Sayori's room. If the player attempts to quit or overwrite a save at this point, the game may show an altered dialog box with a partial, flickering portrait of Sayori's face and distorted text. If the player picks "Yes," the game shuts down and starts Act 2 upon starting it once again.