This series starts off with the protagonist, Gorou, confessing to his childhood friend, Koharu. And with Gorou getting shot down immediately. Koharu states that them going out is just impossible. Gorou’s, of course, devastated hearing that and wants to hear the reason why. However, Koharu says that if her refusal’s already devastating him, whether he’d really want to hear the reason why. And yeah, he actually rather doesn’t. And… she also wants him to get another girlfriend asap.
In between smaller arcs, there are handwritten diary entries from Koharu. In this one she’s obviously tsundere-style overjoyed he confessed and would love going out with him, but sadly, she can’t, because of that. Yeah, no mention what “that” is.
At school, Gorou’s in charge of managing the radio room where all the school announcements are done. Chika, a female friend of his, is head of the radio/announcement/”whatever you wanna call it”-club and usually does the noon announcements. Due to their respective positions, they’ve spent a lot of time together and Chika, a rather engaging and energetic person, ended up pushing her love advice on him. After a prolonged exchange where Chika assumes that Gorou’s confession’d been successful and only questions the extent of where he and Koharu’d gone (love hotel?), it eventually dawns on her that he’s been refused. So now she wants to hear all the details why he fell for her in the first place, since she thinks that an outsider could provide some fresh interpretations here and come up with a clue. After that, she also wants to know what had happened when he got refused. Especially the “get another girlfriend” part strikes her weird, too. Overall, she encourages him to get more infos out of Koharu. Anyway, that’s when she bids all their listeners goodbye since she had put their complete dialogue on the school announcement system all along.
Next it’s time for Gorou’s student council duties. So he meets with Mafuyu, the student council president and chuuni with an eyepatch just like you-know-who, in the student council room. All she does is advice him to not pry further into Koharu’s affairs since no good could possibly come from that.
When Gorou returns home, to his surprise, Koharu is idling in his room as if nothing happened. Noticing his surprise, she asks if she’d better not come. He says of course not and that he’d been worried because of the confession things had become awkward between them. After some back and forth, she asks whether what she’d said yesterday was weighing on his mind. Getting a girlfriend should be an easy task for him since he’s on good terms with that girl in his class. However, when he tells Koharu about her (Chika), she obviously gets jealous. He calms her down saying that they’re really just on good terms as friends. Now Gorou pushes back and asks why it’s so important for him to get another girlfriend. After all, he’d be fine going out with Koharu. Being told that, she flushes. But being pushed by him, she then gets flustered and says that she’s got a boyfriend already.
This diary entry simply states the obvious: It’s a lie and she’s got no boyfriend. She also worries that he’ll find out before long.
Next day, after school, but at school, the rooftop. Gorou is together with his friend, Kureto. He tells her about the confession and his talk with Koharu. For various reasons, Kureto assures him that Koharu couldn’t possibly have a boyfriend, mainly for two reasons: 1) She’s always with him, 2) Gorou would’ve noticed a change in her behavior. So Kureto asks Gorou whether she’d been acting strange in the past, he also wagers that he’ll run around naked if she does have a boyfriend; whyever he’d do that. Anyway, two things are noteworthy: Koharu and Gorou didn’t see each other during the spring holidays, and at the beginning of highschool, Gorou ended up being hospitalized for some reason and while Koharu visited him every day, she grew gloomier by the day but her mood lightened up towards his discharge from the hospital. That leads Kureto to believe that that was the time she’s gotten a boyfriend, so he strips as promised. Chika enters the rooftop right when Kureto frees himself from his briefs and takes a few photos. From there on, he’s being blackmailed in being Chika’s workslave and also acquires the nickname “Tissue,” since a tissue, for whatever reason, had covered a certain part of his body when he stripped naked.
Back at home and with Koharu, Gorou tells her that he can’t make a girlfriend right away, since he’s in love with her, but that he’ll try to move forward step by step. In the meantime, he asks what kind of guy her boyfriend is and whether they’d ever gone on a date and whatnot – after all, she’s always with him. She denies, so he now wants to help with her love life too, so they decide to go on a ‘rehearsal date’ to help her get experience for when she’s having her first date with her “boyfriend.”
The diary entry is just about Koharu thinking that – from all that he’s told her – Gorou’s friends seem to be fun, so she wants to pay a visit someday.
The next day, at school, noon. Gorou’s with Chika again and wants her advice for the date stuff and wants her to promise that she’s not broadcasting that again. So they talk about what to do and where to go on dates and is for some reason very pushy that he has to take Koharu to a love hotel. Bottom line is, it was broadcasted again.
The atmosphere in the student council room is a bit tenser today, since the broadcast was pretty delicate (love hotel and all that jazz). Gorou isn’t exactly a fan of those aggressive interviews from Chika either, so Mafuyu has a solution ready for him: To become Mafuyu’s boyfriend. After all, she says, it wasn’t a coincidence he, a freshman, had been picked as a special helper for the student council – she’s interested in him. Also, she simply wants him to go out with her so that Chika’s broadcasting rampage stops.
After Chika’s super angry that Gorou scratched the love hotels from his date plan and she totally promises not to tail Koharu and him during their date, Koharu and Gorou have their rehearsal date. After they visited several places, a specific location on his date plan piques Koharu’s interest, and to Gorou’s surprise it’s a love hotel that seems to somehow have found its way back onto his list. He tries to talk her out of it, but can’t call it by its name, so they end up in front of it. Koharu still doesn’t seem to realize what kind of place it is and wants to go inside…
This time’s diary entry is about Koharu being totally excited about the date and wondering what to wear.
And so their date begins, after they’ve been to a bunch of things and had their fun, they wonder where to go next. After getting a mail from Chika and setting her on a wrong track as Gorou just knows she’ll try to spy on them, Koharu insists to go into one of the love hotels – not knowing it is one. Gorou tries to talk her out of it without being able to bring himself to tell her what exactly that establishment is, and even when they arrive in front of it, Koharu still doesn’t take the hint. Anyway, they go in and rent a room, the receptionist – a grandma – give them the look you might expect from a Japanese grandma who sees two kids entering such a place, and they enter the room. Gorou does his best to keep Koharu from looking into various lewd things like the (porn) TV guide and sex toy catalog, but it’s no use, Koharu sees the condom on the nightstand and finally it dawns on her. She dashes out the hotel and Gorous follows while getting a mischivious grin from the grandma as her farewell.
It’s getting late and they’re on the playground where they’ve also been as children. After a bit of “I still like you” by Gorou, a girl appears in the playground entrance. It’s Gorou’s other childhood friend who moved to the US during middle school, Akina. Apparently, she came back. Koharu knows her too. However, Koharu vanished before Akina could even take notice of her. Out of nowhere, Chika and Tissue appear too, apparently having been able to find Gorou at last. They end up mistaking Akina for Koharu, since they haven’t met Koharu yet, and they don’t give Gorou a chance to clear up the misunderstanding. And so Chika keeps on talking about how Gorou just can’t stop talking about “her” in school and so on, which seemingly embarrasses Akina. In the end, Chika insists on exchanging mail addresses with “Koharu” to keep in touch with her.
The next day Gorou consults with Mafuyu. He tells her about how Koharu just disappeared and Chika’s and Tissue’s misunderstanding. They try to get on the bottom of why Koharu disappeared. Apparently, when Akina moved to the US back in middle school, she wanted to meet with Gorou to tell him something the day of her flight. However, in the end Akina told him that it’s fine he didn’t need to come. Instead, Koharu seemed to have met with her but told Gorou later that they didn’t talk about anything important. In hindsight, that seems weird to Gorou and Mafuyu and might be the reason Koharu ran away the day before.
Koharu is in Gorou’s room again, he straight out asks her why she ran away, and after she asks him a dozen times over whether Akina told him something, she seems baffled that Akina didn’t. Gorou then brings up that day back in middle school when Akina left and asks her what happened back then. It turns out, Koharu and Akina got into a big fight, which makes is hard for Koharu to face her. Considering how long it’s been since then, he suggests they should make up already, but Koharu states that if girls fight like that, there’s no making up. She also hints quite obviously that Akina has feelings for Gorou, which he – of course – doesn’t pick up on. Anyway, she’s now done talking about all that, which ends this part.
So Chika, Tissue, and Gorou now visit Akina in her small apartment. Before long, of course, Chika and Tissue take their leave under false pretenses and leave Gorou with the mission to help put together Akina’s bed with her *winkwink*. Akina looks kinda tense, which Gorou understands since she’s a girl, he’s a boy, they’re alone in her room, so he assures her that he’ll just fix up the bed and take his leave. A few statements later like that Akina’s parents actually don’t mind Gorou come visit her at all, quite the contrary, Gorou realizes that she’s wearing quite the emphasizing outfit – if you know what I mean – that day. He tries his best to calm down his boner (ya’rly) by shifting the topic to Akina and Koharu’s relationship. He says Koharu really wants to make up with Akina and he wants to let her meet with her.
There’s a small flashback about Akina’s past, how she always had to move with her parents, which was a curse and a blessing – a curse because she couldn’t really make friends, a blessing because it wasn’t just because of her moving around so much but also because of her awkwardness, and so every move was a new chance at not ending up as a loner. However, one day her father told her that the next location they’ll move to will be more permanent, which worried Akina. Sure enough, she kinda ended up being lonely, but she bumped into a boy and a girl who were always fighting with each other quite a lot, Gorou and Koharu. The two ended up talking to her and eventually, they became friends and she even ended up in class with Gorou – but without Koharu – at some point. Seeing them get along so well made Akina feel very happy for them, and yet it hurt her at the same time. She tried hiding her sadness by putting on a happy front to the point that people thought she was even more energetic than before. However, at some point Gorou asked her whether something’s wrong since she seems so sad these days, which burst her bubble and made her break out in tears. Not necessarily because she was so sad about that, but because she was so happy that he paid so much attention to her, and then she realized she’d fallen for him.
Back in the presence, Gorou and Akina made up a plan on how to get Koharu to meet with her. She’s in his room as always, and Gorou agreed on meeting up with Akina and bring her to his room. Akina’s very tense, of course, and they decide to let Akina stay in front of his room and let Koharu know she’s there, so that they won’t totally spook her. And so Akina and Koharu “talk.” Actually, Gorou talks for Koharu through the door. Like, that Akina really wants to talk to Koharu again but is kinda scared to overdo it now too, and – more importantly – Akina says that she’s heard Koharu made a boyfriend; and she says that she thinks Koharu made that up. Furthermore, she repeats that in that past incident, Koharu had gotten mad at her for trying to confess before moving overseas, since if she confessed she was ought to confess with, how to put it, “intention,” and not confess and then “run away.” And so Akina’s now come back to Japan, so she tells Koharu that she’s come to confess this time for sure, and that she wouldn’t run away. She opens the door, and Koharu’s gone. Gorou’s flustered and has no idea where she went, he checks various possibilities, but all Akina does is give Gorou a worried look and ask him whether he’s alright.
Second to last chapter, it’s time for shit to get real: Basically, Gorou’s friends are absent from school. He’s with Mafuyu and she, quite seriously, takes him on a trip. To a clock store. To his old middle school. To an intersection close to his house, where someone seemingly puts flowers on the ground on a daily basis. All the while, she keeps saying cryptic stuff to Gorou about how she chooses to sacrifice one person if it means saving hundred others, and as things stand, Gorou’s gonna drag his friends down with him, but she wants to try to save him too, if possible, and for that she needs to open his eyes first. He staggers back to his home, where Akina is waiting for him in tears, telling him that she talked with Koharu’s mother, and why he wouldn’t acknowledge the fact. The fact that Koharu’s died a while back. Apparently, Gorou’s attending a far away school so that he’s not surrounded by old memories all the time and he’s helping the student council since the school staff thought it’d be better to handle “his case.”
Flashback to when Koharu was young. She noticed that she totally fell for him back when kids stole her diary in elementary school (?) and wanted to read it out loud, he beat ’em up and announced that ‘no one touches my Koharu.’ In middle school when Akina joined them, it was kinda hard for her because she knew that Akina had feelings for Gorou too, but… well, you get the picture of the triangle problematic here. Anyway, during winter, when Gorou’s birthday drew closer, she wanted to give him a watch, since he always wanted one. So she tricks him into getting his measurements and orders a watch for him. When she picks up the watch and walks to the intersection where Gorou is waiting to pick her up, she waits for the traffic signal to go to whatever color signals “go” over there, but slips on the street and gets hit by a car.
That’s her last memory of when she was alive. What she remembers next is being in the hospital and everyone around her crying or being out of it – she died. Her dad gives Gorou the watch box, which is – of course – severely damaged from the accident and tells him that Koharu wanted him to have it. He doesn’t even open it and just spaces out. His parents then sign him up for a faraway school where none of his old friends are present to shield him from painful memories. However, Gorou gets bedridden, not by disease, but by his mental state. Koharu watches over him but can’t interact with him, she’s feeling miserable seeing him be miserable, and she tries to come up with something she could do for him. Meanwhile, his state gets worse by the day, to the point where Gorou gets hospitalized. When he opened his eyes after a few days, he suddenly greeted Koharu, seemingly unaware of these past few weeks. While it did make Koharu happy that he could see her and was doing alright, she also knew that this couldn’t last forever, and it got worse when he confessed to her since there was no way she could go out with him. That’s why she told her once in a lifetime lie.
Gorou visits Koharu’s old room and finds her diary. He reads through it and Koharu watches him doing so. After he’s done, she calls out to him and wants him to part from her. Their whole lives, they’ve been together, so she can’t move on if Gorou doesn’t separate himself from her. She tells him, that she loves him, but that he needs to let go. He, however, simply sighs and then announces he doesn’t care what she is, he’s just glad his love isn’t unrequited and wants to be with her forever, no matter what people think. The book closes with something like, “And thus began a very, very long love, a love between a ghost and a living being.”