Summary
During class one day, Natsumi is surprised to be lent manga from her classmate. Their teacher scolds her for talking during class, then apologizes and returns to teaching. Natsumi quietly chats with her friends about how strange this is, considering he and their Teacher usually get on her case. Her friends don't notice anything wrong, going on to discuss the upcoming supplementary lesson their class is taking during summer. While they don't want to do it, they realize Natsumi will have a good opportunity to get closer to Nakatani; her crush.
- - - -
After their supplementary lesson ends, Natsumi attempts to approach Nakatani to give him a cellphone strap she bought for him. Her friends convinced her to do this, pointing out how popular he is. Things become awkward when she confesses her crush on him and they find themselves surrounding by their friends, who encourage Nakatani to respond to Natsumi. They recall that he wanted to say something to her. Nakatani and Natsumi discuss calling each other later when they get home.
- - - -
Natsumi mopes as things return to normal, telling her friends that Nakatani never called her. She doesn't know what happened, and she attempts to play it off when they confront him. The duo speak in privacy and Natsumi tries to tell him its fine, assuming he probably just forgot. He suddenly asks that she not speak to him anymore, much to her alarm. Natsumi asks why, and he mentions their supplementary lesson before leaving. She quickly returns to her friends to fill them in on what happened, and she recalls that he was glaring at her earlier. Like he was angry. The girls assure her its nothing, but it doesn't work. Natsumi can't remember having done anything to make him dislike her.
Class resumes and Natsumi takes notice of how eerily quiet everyone has become, and now they're actively avoiding her. This confuses her but her friends say that she didn't do anything wrong, and they point out that she was sleeping during the bus ride home from that lesson. They assure that they will remain by her side regardless, but this brings her little comfort. She attempts to speak to Nakatani during break, offering to play soccer with him. He ends up glaring at her again and her friends stick up for her, telling him to be nice. Natsumi attempts to follow after him when he leaves but they stop her, suggesting its a lost cause. She agrees, but by now something doesn't feel right.
Suddenly, Natsumi feels light-headed and like she's under water. She snaps out of it after her friends start to worry and one of them grips her wrist. She insists she is fine and they head back to class, only for her to realize she now has strange bruising on said wrist. During class, Natsumi makes the realization that since that supplementary lesson a while back, things haven't been the same. Everyone has been acting different.
During the next break Natsumi confronts Nakatani to ask what happened when they were out by the sea. She voices her concerns and how she can't remember anything now. It's then she realizes that her classmates have returned to the room to spy on her. She tries to brush it off and they calm down, allowing Nakatani to grab her arm and run down the nearby corridor. The crowd becomes angry and demand he release her, even calling the Teachers to stop him. Natsumi is bewildered but Nakatani offers to explain once its safe.
- - - -
Outside, they come to a bus that will take them back to where their lesson was. Everything from behind starts to vanish, and Nakatani suggests that Natsumi stop thinking about them. She is shocked he would suggest this, and she refuses after recalling her friends promise to stand by her side. She wants to remember what happened so that everything returns to normal.
Having returned to the sea, Nakatani leads Natsumi closer after they realize the others have caught up to them. Her friends beg her not to listen to him and Natsumi feels anxious, but she isn't sure why. Until she recalls earlier, when she felt light-headed, like she was beneath water. She realizes that back on that day, during the supplementary lesson she was under water. With everyone else.
Natsumi releases Nakatani's hand to ask if she was killed, wondering if this is why everyone has been treating her so well as of late. Nakatani dismisses this as they overlook the cliff side, and he tells Natsumi to leave. She refuses as she she thinks about her friends and him- she had plenty of experiences and memories she doesn't want to miss out on. She doesn't want things to end like this.
Suddenly, Nakatani embraces Natsumi and pleadingly asks her to leave again. He tried so hard to be cold to her, she shouldn't be here. As her friends approach them, Nakatani apologizes to Natsumi for being unable to keep the promise they made that day. He releases her and she falls from the cliff.
- - - - -
Natsumi awakens in the hospital with her parents. The doctor returns and they explain that she was in a bus accident on the way home from the sea side. They didn't think she would make it, and they reveal the newspaper article published recently after it happened. Thirty-two people are still missing from the accident, she was the only one found. Natsumi is dismayed as she recalls the bus falling and filling up with water. Everyone was panicking as Nakatani opened one of the windows wide enough for her to get out while he stayed to help the others. Natsumi cried and begged him to come with her, but he promised they would reunite later. He forced her out of the window to swim to the surface. The bus continued sinking down further into the depths of the sea.
It's then her dad reveals that Nakatani gifted her something from that day. It was in her pocket. She takes the object to see a shell in a small bottle, like the strap she gave him. She clutches it and begins to cry.
- - - -
With time to grieve, Natsumi returns to the sea side a while later and approaches the lighthouse. She throws a bouquet of flowers over the cliff for everyone who lost their lives that day. In memory of Nakatani, she wears the seashell charm on her neck. Her dad approaches to collect her and Natsumi turns, just to see Nakatani's spirit. In his hands, she sees the charm she gave him. She smiles as he vanishes and she begins to head to the car.
She has come to the decision to keep moving forward.
Tropes:
- Dead All Along: Everyone with the exception of Natsumi and her parents, and the doctor.
- Famous Last Words: "I'll come out later! I promise! I'll get out! I'll definitely get out!"
- Heroic Sacrifice: Nakatani forced Natsumi to exit the bus knowing she could make it out alive.
- Never Found the Body: Natsumi reads the news article to learn that the other thirty-two passengers on the bus weren't found.
- Sole Survivor: Natsumi
- You Are Not Alone: Natsumi's friends assure her of this when she starts to feel upset over Nakatani's sudden cruelty.
