Cover of volume 3:
Nagi skipped class for a day to hang out with her boyfriend, Tokiwa. She sensed that she'd changed, and wasn't sure she wanted to keep seeing him behind their parents' backs. They had a fight about it, and then as he was walking away, he got hit by a car; his injuries were relatively minor, but he asked her how she'd have felt if he had died. Nagi's dad came to pick her up from the hospital, and she told him that she'd been lying to him. She apologized to her parents. After that incident, her father gave in and stopped trying to keep her from seeing her Tokiwa.
Nagi went to visit Tokiwa in the hospital, and they got into another fight. At the end, she told him that she didn't want to see him again after his injuries healed, because she'd realized that if he had died in that accident, she'd have grieved but would have fallen in love with someone else. He tried to call her a few times after that, but she pretended she wasn't home, and he gave up.
At school, Nagi ran into an old friend and ended up eating lunch with her and Sato. They told her that someone found a pregnancy test in the third-years' bathroom, and it was positive. Nagi and the other girl also discovered that Sato was worried she might be pregnant, though she wasn't the one who left the pregnancy test in the bathroom. The baby's father wanted to marry Sato, but she wasn't sure if that was what she wanted--she had other dreams.
Nagi ran into Tokiwa at a bookstore. He told her that he understood why she broke up with them--that they were on the verge of drowning. He made it clear that he was open to the idea of going out with her again if she wanted. But she was still scared.
Sato took a pregnancy test, with Nagi and the other girl there for moral support. She confided in them that the baby's father had told her that she didn't have to give up her dreams even if they got married and she had a kid--that there would still be a chance for her to go to college. Her plan was to marry him if it turned out she was pregnant. However, the test result was negative. (This whole situation seemed to be engineered by the author to show Nagi that Sato wasn't running away from happiness.)
Hiro was called into the principal's office, where he talked to her about some university of music that wanted her. She got dizzy and collapsed, and they took her to the infirmary. Nagi oh-so-conveniently ended up going to the infirmary shortly after, and saw a note from the school nurse saying that they left to take Hiro to the hospital. Nagi reflected that she hadn't talked to Hiro in a long time; she wanted to patch things up with her, but it just wasn't possible at that point in time.
However, that evening, she got a call from Hiro's mom. As you've probably guessed, the mysterious pregnancy test was Hiro's (and she was 8 weeks along at the time of the phone call). Hiro didn't say who the father was, so Hiro's mom asked Nagi about it. Nagi, of course, had no clue that anything was going on with Hiro at all.
Hiro and her mother have been talking to some school official, who's said that they're willing to sweep the pregnancy under the rug (assuming she gets an abortion). Hiro's been silent the whole time, and the official has asked if she plans to drop out of school and get married (even though she still hasn't told them who the father is). He's told her that she needs to consider her current position. Her reply: "If you want to kill the child that badly, I'll do it for you right now."
She opens the window and makes to jump out of it. Nagi, who has been listening at the door the whole time, bursts in and cries her name. Hiro goes to her, repeating her name over and over. Nagi realizes that Hiro's been crying out to her for help this whole time; she just didn't hear her...
Nagi sat by Hiro's bed in the infirmary, and asked Hiro what she planned to do. Hiro told her that she wasn't going to see the doctor anymore, and that she had no intention of telling him about the baby. Nagi wondered why--didn't Hiro love him? Was she protecting him? Either way, Nagi couldn't just leave things be. She went to see him.
He asked her to wait for him in a staff lounge, and as she was sitting there, she overheard some other doctors talking about how he was engaged to be married to someone else, how he made some woman get two abortions, and how they'd seen him meeting with Hiro outside the hospital. She confronted him about it, and he told her that Hiro knew about his fiancée from the beginning. When she blurted out that Hiro was pregnant, he gave her the name of an OB-GYN and told her that he'd cover all the fees (for an abortion, presumably). Then he gave her some money and told her not to come to the hospital again. She ripped up the money, flung it in his face, and started hitting him on the chest, asking how he could do such a thing and act so normal about it (go Nagi!).
Inside her head, Nagi pleads Hiro to stop hurting herself.
Hiro calls Nagi from a phone booth and asks her to come with her--Hiro can't stay at home anymore, and Nagi is the only person she has left. Nagi silently vows to stay by Hiro's side. She leaves a note for her parents telling them that she's going with Hiro and that they shouldn't worry about her.
Nagi met Hiro at the train station. Hiro told her she wasn't sure Nagi was going to come, and hugged her. On the train to Hiro's family's summer home, Hiro apologized for always being such a nuisance, and told Nagi that this was the last time she'd ask Nagi to indulge her. Nagi didn't understand what Hiro meant by that, but felt that all she could do at the moment was accept whatever answers Hiro gave her.
When they got to the summer home, Hiro asked Nagi if she would stay there with her for a little while, and Nagi agreed. Hiro didn't say anything about the pregnancy, so Nagi decided she'd just have to try and help Hiro take good care of her health for the time being.
As Nagi looked around the summer home, she was reminded of how wealthy Hiro's family was, but how all that wealth couldn't necessarily give Hiro what she wanted or bring her happiness. She came upon Hiro playing piano (the Moonlight Sonata), and sat down at the bench with her.
Sitting there with Hiro, Nagi silently reflects that Hiro feels close by again for the first time in a long while. Hiro says that she wishes they could stay like this forever--that the world would stop and tomorrow would never come.
Hiro asks Nagi if she can get in her bed with her, and Nagi says yes. Nagi comments that it's like they're on a field trip together.
They make breakfast together the next morning. Hiro accidentally slams into something (the counter?) and Nagi worries that she's hit her stomach. Hiro says she's fine, but Nagi makes her sit down anyway.
Nagi and Hiro went to a river near the summer home. Hiro told Nagi that the river lead to a waterfall, and that she'd gone there once and tried to kill herself; her father had stopped her, and they hadn't been back to the summer home since. Hiro also confided in her that as a child, her education had focused on the piano, not on relating to others, and so she never understood why she was disliked. She couldn't smile properly, or come up with topics of conversation; and yet people had gathered around her. She'd wanted to stop playing piano. And then when it had happened for real (because of her injury), everyone had became indifferent to her--they no longer cared whether or not she existed. She'd wished she could be like Nagi instead.
As Hiro cried in Nagi's arms, Nagi reflected that time was running out--Hiro was around two months along... Hiro told Nagi that she'd asked the baby over and over whether it wanted to be born or killed, but hadn't gotten an answer. Suddenly changing topics, she asked Nagi if she (Nagi) was happy. Nagi said yes, but Hiro persisted, asking if Nagi was really happy without Tokiwa. Hiro apologized to Nagi, saying that Nagi would never have broken up with him if it hadn't been for her. Nagi tried to tell Hiro that it wasn't her fault, but Hiro interrupted her, asking why people hurt other people. She wondered if the child would end up hurting people and being hurt in turn, and if it would resent her if there weren't many good things in its life--if she'd bring it unhappiness by raising it. She couldn't give birth to a child in that situation.
Nagi asked Hiro if she'd come to a decision, and she said that she'd made her decision right at the beginning. Nagi began to cry, and Hiro asked her why she was crying. Nagi realized that she'd been dreaming of Hiro becoming a mother, and living with the child the way she was living with Nagi just then. She'd thought Hiro and the child would've been happy together. (As Nagi was thinking all this, Hiro suggested that they go back home the next day.) Nagi realized how foolish that was--the reality was that Hiro was a high school student, and there was nobody to be a father to the baby. Hiro must've known from the beginning that she couldn't have the baby.
When Nagi woke up the next morning, Hiro was gone. She suddenly wondered why Hiro had needed to leave home and come all the way out there, if she'd already made her decision. She ran out into the forest, calling Hiro's name.
More coming soon.