26-year-old Momose Narumi is a die-hard yaoi fangirl geek who recently switched jobs, in hopes of being able to play off an image of a perfect, beautiful young lady. However, her hopes are crashed when she reunites with her middle school classmate Nifuji Hirotaka, an avid gamer nerd that knows about her secret. Both reconnect over alcohol and Hirotaka promises he will not tell on Narumi's geek secret, commenting on how love is difficult for people like them because others think they're "abnormal" and "weird". Two weeks later, Narumi invites Hirotaka out for drinks again but is unable to finish her work on time, prompting Hirotaka to stay back and help her before they go out. As they drink, Hirotaka asks Narumi out, offering to help her pass her game levels as a benefit. Excited, Narumi accepts.

Narumi befriends Koyanagi Hanako, her coworker and also a famous nerd who specialises in cosplay. Hirotaka notices Narumi blatantly avoiding him at work because she is unsure how to interact with him now that they are in a relationship. Kabakura Tarou, Koyanagi's long-time boyfriend and Hirotaka's good friend, steps in with Koyanagi to help but end up fighting with each other instead. As Narumi attempts to run away, Hirotaka apologises for frightening her, promising that he is actually romantically interested in her and not just dating another nerd for convenience. After work, the four visit a bookstore, and end up departing for their own homes right after to read manga and play games instead of drinking.

Narumi, Hirotaka, Koyanagi and Kabakura attend a comics expo. There, Hirotaka helps Narumi take care of her yaoi fanzine stand, while Kabakura watches Koyanagi cosplay as multiple male characters.

Work resumes as per normal for the four after the expo. When Narumi goes to Hirotaka's place to play video games with him, she is initially really nervous about being alone with him, but Koyanagi and Kabakura join them soon after. As Hirotaka takes a shower, Koyanagi and Narumi mischievously attempt to search for his hidden porn stash, but Narumi finds a pack of old card games they used to trade and play together back in middle school instead. The two reminisce how the two of them sparked a friendship after they exchanged character pencils with each other, and Hirotaka kisses Narumi. The next day, Kabakura shockingly finds a mysterious porn stash hidden in his desk drawer.

Hirotaka and Narumi indulge in their childhood anime together during break at work. When Narumi shows off a picture of Hirotaka cross-dressing to Kabakura and Koyanagi, this inspires Koyanagi to make Kabakura cosplay as well, but this culminates in them arguing. Narumi comments on how despite her and Hirotaka having different interests they are willing to compromise with each other fairly to work things out. Eventually Kabakura cosplays for Koyanagi in exchange for a high quality Yuudachi Kai-II figurine.

The four coworkers go out drinking together. Narumi asks about how Koyanagi and Kabakura's relationship began back in high school, but this leads to a string of arguments and causes the drunk Koyanagi to break down. She confesses her hidden insecurities about how she is not Kabakura's real type, and worries that he might just be settling for her because nerds usually find it hard to be in a stable relationship with non-nerds. At that, Kabakura steps in and comforts her. On the way home, Narumi asks the same question to Hirotaka, who reassures her once again that he is properly invested in this relationship. The two decide to head to the arcade first before going home.

Narumi bumps into a barista in a cafe whom she seems to be familiar with. Koyanagi and Kabakura mistakenly believe that the barista could be Narumi's ex-boyfriend, and debate about whether to call Hirotaka to the cafe. However, when Hirotaka does in fact enter, Kabakura hastily calls him to prevent a scene, causing both him and the barista to respond. In turns out that the barista is Nifuji Naoya, Hirotaka's younger brother.

Hirotaka reluctantly agrees to Naoya staying at his house due to its proximity with the latter's college. As the four coworkers hang out at his place, they realise that Naoya is a non-nerd and decide to be careful about talking around him. As this is a rare chance for the brothers to be together, Narumi proposes a team game and groups the brothers together, albeit Hirotaka's unwillingness as Naoya's inexperience and lack of player skills often diminish the fun. Naoya ends up self-destructing and Hirotaka, used to playing solo, wins on his own, falling asleep on the couch right after. As Naoya decides to walk Narumi home, Kabakura, still suspicious of him, informs him that Narumi and Hirotaka are dating, and Koyanagi kisses Kabakura to show that they are another couple themselves. Naoya begins to tear up out of happiness because he had been worried his brother would end up alone due to his personality, and Kabakura is touched by Naoya's sincerity towards his brother. The next day at work, he advises Hirotaka to take care of him.

On a rainy day, Kabakura lends both Narumi and Hirotaka his umbrella after realising that they both forgot theirs. As he dashes in the rain, he finds and ducks under Koyanagi's umbrella, where she worries about him falling sick as they head to his home to eat dinner together. The next day, Hirotaka notices that Narumi is a little down, although she tries to brush it off to no avail. After a little comforting and pressuring on Hirotaka's end though, Narumi explains that her favourite manga character died recently in a chapter.

Hirotaka and Narumi walk home together as the city puts up Christmas decorations. They find Naoya giving out coffee samples in a Santa Claus suit outside the cafe, who feels grateful for being able to make those around him smile, and be their "real Santa Claus". On Christmas Eve, Koyanagi, who had been annoyed because Kabakura was too busy with work to care about romantic things last Christmas, leaves the office first, but Kabakura rushes after her. The two of them end up on a date at a fancy restaurant which Kabakura reserved half a year in advance to make up for last year, and Koyanagi gifts him a limited-edition anime plushie. Meanwhile, Hirotaka and Narumi spend their first Christmas together playing games.

The four play an online adventure game together. In there, Narumi, Koyanagi and Kabakura stumble upon a rare enemy, but are too weak to defeat it. Hirotaka's avatar arrives, but it is being controlled by Naoya at the moment as Hirotaka is busy. Thankfully, Hirotaka quickly returns and defeats it easily.

Kabakura goes out drinking with his male juniors, including Hirotaka, whilst the women hang out together for dinner. Two male coworkers start discussing about Narumi, unaware that Hirotaka is her boyfriend, and then about Koyanagi, which angers Kabakura although he tries to hide it. Narumi and Koyanagi, on the other hand, disagree again about their opposite pairing preferences in anime and discuss about having their boyfriends paired in a boys' love situation. Later, Naoya tells Hirotaka about how he overheard the girls' conversation and mistakenly believed that they were arguing over whose boyfriend was better.

It is a windy workday and Hirotaka confesses that he is afraid of thunder as it brings back a lot of bad memories of unsaved games when the power went out from lightning. To prevent it from disrupting his productivity, Kabakura allows him to wear his headphones just for today. As Hirotaka goes for a smoke, followed closely by Narumi, he reminisces how she came to visit him once when he was sick, and ended up barging into his house and hugging him due to the loud thunder outside. The two return to work, as the sky grows lighter with the passing storm.

Hirotaka recalls how he pierced his own ears when he was in high school in an effort to seem grown-up after seeing Narumi with a boy with piercings. When he was unable to pull the earring out, it had begun to hurt and he had cried. After some drinks with everyone, Hirotaka thinks back to how Narumi does not seem to see him as a boyfriend, and worries over how he is so different from a "regular boyfriend", especially in his date choices and attitude. When the two walk home together, Hirotaka decides to ask her out on a conventional date next Sunday.

Hirotaka and Narumi go on a date at an amusement park, but this date has a special penalty attached in that anyone who says anything nerd-related has to pay 500 yen to the other party each time. While going on a horror ride together, Narumi's fear accidentally causes her to carelessly pair up with Kabakura instead, while Hirotaka goes on with Koyanagi, as the two are also on a date here coincidentally. Koyanagi assures Hirotaka that it is okay to move at their own pace in a relationship after he reveals how he is worried if Narumi really likes to spend time with him. At the end of the day, he thinks back to how Narumi had always dragged him around as children, and how she really has grown up and made many memories while he has not at all, and still is cooped up in his own little world playing games. The two eventually lift the penalty and immediately feel a lot more relaxed. Narumi then gifts him a pair of earrings and asserts her desire to witness the "wanting to become more adult-like" side of him that she never saw, and the two hug. However, Hirotaka later realises that one of his earholes had closed up.

Naoya meets a customer at his part-time job, whose silhouette while playing games reminds him of his brother. The following day, he bumps into the same person again at his university cafeteria, and introduces himself. He realises that the person, Sakuragi Kou, is an avid gamer like his brother, but does not realise that she is a girl due to her androgynous appearance and voice. Knowing his lack of experience in gaming, Naoya invites Kou to play games with him, and reaches out to Narumi and her friends for help to improve his skills by then. While battling to clear an advanced quest, a mysterious player saves them while in a pinch before Hirotaka arrives. Naoya, figuring that it was Kou, thanks her over message.

Hirotaka breaks his glasses in the morning, so as a result his myopia hinders him greatly in doing his job. His female coworkers become conscious of his handsome face without his glasses, making Narumi distracted and jealous. To let both of them regain their concentration, Kabakura lets them off for an early lunch break for Hirotaka to get new glasses. Later, Naoya borrows his brother's computer to play multi-player with Kou. Despite trying time and time again, Naoya continues failing, but Kou does not give up on him, and is more than patient enough to help him improve gradually. Hirotaka, intrigued by Naoya's sudden addiction to games, logs on as the latter's avatar and helps Kou clear a quest. Naoya, returning to the game after picking up a phone call, apologises and decides to drop out, but Kou promises to help him and invites him to play together.

Koyanagi reminisces the times when her and Kabakura were always fighting for the gym, as captains of the female and male volleyball team respectively. Meanwhile, Narumi buys some snacks for Hirotaka on the last day of vacation, only to find him passed out on the floor due to not eating and sleeping to play games. She decides to cook some fried rice for him while calling Koyanagi, only to accidentally see Hirotaka naked after he takes a shower. Back at Kabakura's house, him and Koyanagi get into another argument over boys love manga, with Koyanagi confessing that she wants to share her happiness with others although she knows he is the type to enjoy things himself. This leads to Kabakura compromising and agreeing to skim one, and he surprisingly enjoys it. Narumi orders Hirotaka to go on a date with her, but they detour to her house afterwards to watch a variety show starring her favourite voice actor, with Narumi promising to cook for him again. Kou goes around town trying to find Naoya after noticing that he has not logged in in a while, and gives him a game strategy guide she made herself.

In a post-credits scene, Narumi asks Naoya about his first love, which he bashfully reveals to be his kindergarten teacher. As the four coworkers leave the cafe after their break, Naoya comments how Hirotaka managed to date his first love, although the latter quickly shuts him up with a look.

Narumi and Hirotaka bump into Koyanagi at the coffee shop, who mentions she'll be going with Kabakura to a 2.5D show about high school volleyball. They recall how the two used to be volleyball captains in high school, in 2nd and 3rd year respectively, with Koyanagi saying how they used to be like enemies, prompting them to pressure her to tell them how they eventually become a couple. In high school, Koyanagi and Kabakura used to fight over getting time to practice in the gym, with Kabakura using his seniority and tenacity to force the girls out. However, Koyanagi blackmails Kabakura with a photo of him looking at otaku merchandise, begrudgingly giving the girls more time to avoid being exposed. Sometime later, Kabakura sees Koyanagi practicing jump shots alone, and in an attempt to show off, inadvertently leads Koyanagi to become entranced by his skill and asks him to teach her, which he agrees if she deletes the photo. Back at the coffee shop, the two listeners debate who confessed first, with Narumi choosing Kabakura, and Koyanagi for Hirotaka, before she continues her story. During their practices, Kabakura lets slip that he imagines his favourite anime theme song whenever he does his jump shots, which Koyanagi admires thanks to his earnestness about his feelings. During the final game before graduation, Kabakura's team loses and he is consoled by a just as heart-broken Koyanagi. After graduation, the two meet outside thanks to a letter Koyanagi wrote. They exchange their usual quips towards each other before heading off in their separate directions, with ultimately the two of them turning around to embrace the other, not wanting to lose their relationship. After finishing the story, Kabakura rushes in to scold Koyanagi for spilling it all to them, with the two once again arguing over who actually hugged the other first. Narumi and Hirotaka secretly look over to Koyangi's phone, realizing she never actually deleted the photo, and as her and Kabakura head off to their show, Narumi comments that she knows why she could not delete it.

Kou goes out to the arcade with Naoya and his friends, where she feels self-conscious over still not telling him she is a girl. He accidentally spots her coming out of the girls' bathroom, leading him to become surprised at the realization, while she runs away embarrassed. Naoya goes to Hirotaka and Narumi for advice when Kou stops showing up to school, and logs into Hirotaka's user account to try and contact her in-game. After some attempts at the two apologizing to each other, and having fun working together to evade an enemy, they reconcile. Later, Naoya, while accompanying Hirotaka and Narumi on a date at the arcade, runs into Kou again, as the four hang out, with Hirotaka and Kou bonding over their skill levels. Kou is initially a little jealous of Narumi, but is relieved when she learns she is not with Naoya. On another day, Naoya receives tickets to the movies, and with encouragement from his friend, invites Kou out who, with help from Narumi, arrives in more feminine clothes, to Naoya's surprise. She also remembers a conversation with Hirotaka where he thanks her for being so close to him. After their date, Kou admits to how much better she feels whenever she is around Naoya, saying she likes him and wants to stay friends forever; Naoya's slightly caught off guard but still happily accepts. As they head their separate ways, the two reflect on their feelings on what they want in their relationship.

The office is preparing a retreat at a hot springs inn for the employees, with Koyanagi against it, Narumi for it, and Hirotaka indifferent to it, until they learn Kabakura is in charge of planning, so all agree to join. Having never been on a trip since school, Hirotaka requests Narumi's help in finding the essentials to pack. Because of this inexperience, Narumi wants Hirotaka to grow friendlier with the other employees, though Hirotaka secretly desires some alone time with her. On the trip, Hirotaka ends up having fun with some of his co-workers, with Narumi feeling slightly jealous. That night while in the bath, the girls and boys each voice their respective feelings of wanting to be closer, resulting in a drunken Kabakura getting slightly intimate with Koyanagi and Narumi and Hirotaka spending some time together outside (under the guise of her playing a gatcha game). Sometime later, the four, plus Naoya and Kou, meet up to have a gaming party, where Narumi asks Hirotaka if he'd like to go on a trip that she plans next time. Back at work, Narumi and Koyanagi fantasize over how all their relationships would be if they were all gender-swapped.