It tells the story of Hinako Mukaimizu, a 19-year old girl with a passion for surfing who moves to an oceanside town in order to attend college. There she meets Minato Hinageshi, a 21-year-old firefighter who saves her when her new apartment catches fire. The two of them fall deeply in love, with plans to get married in the works. Unfortunately, that all changes one morning when Minato sacrifices his life to save a drowning boater, but Hinako realizes that she can summon his ghost into nearby bodies of water through singing.
This film provides examples of:
- Accidental Pervert: Minato sees Hinako in the bath, but it wasn't his fault because she's the one who summoned him.
- The Ace: Minato was an excellent cook, decent surfer, brave firefighter, liked by many people, and a Chick Magnet. Yoko reveals that a lot of it wasn't because he was naturally talented, but because he practiced and worked hard.
- Always Second Best: Wasabi feels inferior in comparison to Minato. Yoko bluntly states to him to stop trying to fill in Minato's shadow and be his own person.
- Animal Motif:
- Minato is associated with turtles. He has turtles on his phone lockscreen, tells stories about how the baby turtles struggling on the beach inspired him to work hard, and ultimately, the turtle-print swimming trunks that he wore as a kid are what allows Hinako to remember him as the boy she rescued all those years ago.
- Meanwhile, Hinako and Minato's relationship is associated with the finless porpoise. There's a keychain of one hanging in Minato's car when they go on their first date, they get matching phone cases that look like its face, and after he becomes a ghost, Minato ends up possessing a giant inflatable version that Hinako bought for him as a gift.
- Both Hinako and Minato describe Yoko as a "blue-ringed octopus".
- Annoying Younger Sibling: Yoko is a Bratty Teenage Daughter with a "sharp tongue."
- Because You Were Nice to Me: In the past, Wasabi defended Yoko to her parents when they criticized her for skipping school and not being more like Minato. It's the reason she started falling for him.
- Bittersweet Ending: Hinako and Yoko are saved from the fire thanks to Minato. The ones responsible were arrested. A year later, both Yoko and Wasabi are dating with the latter being more confident. The couple are still close friends with Hinako, who has received her CPR certificate and is now a lifeguard. However, Hinako is no longer able to communicate with Minato's spirit like she once was able to and is still in mourning. That being said, she's still "riding her own wave".
- Bridal Carry: Both Minako and Wasabi do this to Yoko at different times during the climax.
- Cartwright Curse: Minato dies under a circumstance that is completely unrelated to Hinako.
- Character Development:
- Hinako steadily moves past her grief over Minato and "rides her wave".
- Yoko gradually softens up and is more open.
- Wasabi gains more confidence and stops trying to emulate Minato.
- Chick Magnet: Besides Hinako, other women flirted with Minato.
- Cold Turkeys Are Everywhere: After Minato's death, Hinako sees constant reminders of him and the activities they shared in together, from surfing to coffee to marine animals they both liked.
- Color Motifs: Yuasa intentionally used Orange and Blue Contrast between the flames and the water throughout the movie. Besides that, Hinako is seen in a lot of orange and Minato is seen in a lot of blue. Wasabi also wears green a lot.
- Declaration of Protection: Minato promised to be there for Hinako whenever she needed help. He kept his promise even after death to become her Guardian Entity.
- "Do It Yourself" Theme Tune: The film's theme song, "Brand New Story", is performed by Generations from Exile Tribe. Ryota Katayose, one of the group's lead singers, is the voice of Minato. This carries over to the English version, which is sung by Hinako and Minato's voice actors.
- Falling-in-Love Montage: Hinako and Minato's first date is followed by a montage of all their subsequent dates and moments together, including camping, fireworks, running together on the beach, and more. This is echoed later, when after Minato's death, Hinako tries to bring his ghost on all those same activities.
- Foolish Sibling, Responsible Sibling: A downplayed version. Minato has always taken care of himself and Yoko when they were younger and their parents even stated Yoko should be more like him. From Yoko's part, she did skip school but apparently stopped before Minato's death and was more impulsive than him at times.
- Forgotten First Meeting: Two examples.
- Early in the film, Wasabi accidentally sprays himself and a passing Hinako while practicing with the firehose. She lends him her towel and asks for directions before going home. Even when she starts dating Minato and gets to know Wasabi as his friend, she doesn't realize that he was the firefighter from that incident until he brings it up.
- More dramatically, Hinako was the one who saved Minato from drowning when they were children, but doesn't realize until she sees a picture and recognizes the turtle on his swimsuit. It's strongly implied that he did recognize her, though.
- G-Rated Sex: There's a scene where Hinako in a bikini entering a wall of water with Minato in it, with close-ups of her chest as she tries to touch him and swims with him. This is a little ironic considering that there was a scene that depicted them having sex earlier in the film.
- Ghostly Advisor: Only visible to Hinako as a ghost, Minato does his best to advise and encourage Hinako.
- Guardian Entity: After dying, Minato returns as a ghost to protect Hinako by doing things like stopping her and her belongings from falling into ponds, and saving her life by putting out a massive fire.
- Her Heart Will Go On: While the ending shows that Hinako is still grieving Minato's death, she's also moving forward in her life.
- Heroic Sacrifice: Minato dies while saving a drowning victim from a boating accident. To a certain extent, the end where Minato uses massive amounts of his powers and passes into the afterlife may also count, since it means that he and Hinako can no longer talk to each other.
- Hopeless Suitor: Wasabi to Hinako, as she's in love with the departed Minato. Wasabi does move on to Yoko.
- Important Haircut: Wasabi gets a haircut at the end of the film to show that he's given up on Hinako, and he is dating Yoko at that point in the story.
- Intangibility: It's shown that even when Hinako physically enters the water, Minato's ghost still can't touch her - he just phases through her hands or turns into bubbles.
- I Want My Beloved to Be Happy: When Hinako reveals to Minato about Wasabi's Love Confession to her, he's surprisingly understanding about it, stating that Wasabi is a Nice Guy and he doesn't want Hinako to be with someone (in this came Minato himself) she can't even touch.
- Jerkass Has a Point: Yoko is noted to be "sharp tongued" and she is, but she's mostly correct in her statements — Hinako shouldn't keep blaming herself for Minato's death and move on, Wasabi should stop comparing himself to Minato, and so on.
- Jerk with a Heart of Gold: Yoko is a sharp-tongued young woman with little tact but is ultimately a decent person.
- The Lost Lenore: Minato becomes this to Hinako, as his death nearly destroyed her.
- Love Confession:
- Wasabi does a failed one to Hinako when he visits her at her job. She freaks out.
- Yoko gives one to Wasabi after saying he's better than he believes.
- Ms. Fanservice: Hinako has a few scenes in a yellow bikini.
- My God, What Have I Done?: Minato tells Hinako she needs to learn how to live without him, which she doesn't take seriously. However, Minato is forced to stay with her when she begs him not to go to heaven, and this makes her realize that he is right and she is too dependent on him.
- No Antagonist: There's no Big Bad in the movie. The only ones closest to this are just irresponsible young men who break rules but aren't outright villainous.
- Old Fashioned Row Boat Date: Hinako is briefly seen going on one with Minato's ghost.
- O.O.C. Is Serious Business: The usually stoic and straight faced Yoko is crying into Hinako's lap when they're both surrounded by flames.
- Our Ghosts Are Different: After dying in water, Minato turns into a ghost who has the ability to manipulate water, but is only capable of appearing to his girlfriend after she sings the song that was important to both of them.
- Rescue Romance: Happens repeatedly throughout the story. Minato becomes interested in Hinako after she saves him from drowning as a child, Hinako becomes interested in Minato after he saves her from a fire, and Yoko becomes interested in Wasabi after his words "save" her by encouraging her to be herself.
- Returning the Handkerchief: Ultimately subverted. When they first meet, Hinako lends Wasabi a towel to dry himself off with. Although Wasabi develops a crush on her, Hinako ends up with Minato instead, Wasabi's attempts to romantically return the towel after Minato's death end in failure, and he eventually ends up in a relationship with Yoko.
- Second Love: Yoko becomes this to Wasabi after he's rejected by Hinako and they start to bond.
- Sexy Discretion Shot: One moment of Hinako and Minato's Falling-in-Love Montage shows them underneath a cover of some sort, possibly naked, and kissing one another.
- Shipper on Deck: The one-year Time Skip shows Hinako is this for Yoko and Wasabi as she gives them some alone time to do a romantic activity.
- Shout-Out: Images of Lu and the merpuppy can both be seen at points; the former appearing on an image at the fire station, and the latter appearing on a t-shirt as well as some other merchandise.
- Shown Their Work: The CPR techniques shown in the film are accurate on how to implement them in drowning cases.
- Single Woman Seeks Good Man:
- Hinako falls in deeply in love with the funny, friendly, and brave Minato. It's no wonder she's not over his death.
- Yoko has feelings for the good-hearted, if insecure, Wasabi.
- Time Skip: One year goes by after the climax.
- Title Drop: Minato repeatedly expresses a desire for Hinako to "Ride [her] Wave".
- Too Good for This Sinful Earth: Minato is selfless, caring, and capable. After his death, when Yoko and Wasabi drop off his belongings to Hinako, Wasabi starts sobbing about him, expressing his shock at how someone as reliable as Minato could die so soon.
- Took a Level in Badass: The insecure Wasabi becomes more aggressive and confident which makes him a more able firefighter.
- Took a Level in Kindness: While she doesn't lose her sharp-tongued nature, Yoko does soften up to both Hinako and Wasabi.
- Trademark Favorite Food: Hinako's favorite food she eats throughout the movie are omelette rice.
- Tragic Intangibility: A huge part of the plot is that since Minato can only appear in watery reflections, he can't do anything a real boyfriend can. So when Hinako needs someone to help her up when she falls or wants someone to hug her, he can't do anything for her. Hinako refuses to admit this bothers her, but Minato wants better for her and begins to doubt if he's helping her move on.
- Trailers Always Spoil: The trailer and the DVD cover both show Minato's ghostly form, while the trailer also explicitly spoils Minato's death and return as a ghost.
- Tsundere: Yoko is very harsh towards Minato, Hinako, and even Wasabi, though they are all people she clearly cares for a lot.
- Unfinished Business: Minato's promise to always be there for Hinako is part of why he sticks around as a ghost.
- Unintentional Final Message: Hinako receives two of these from Minato.
- When she finally manages to unlock his phone, she finds the text message he was in the middle of composing when he died - he'd just completed the complicated surfing trick he was practicing, and was looking forward to seeing her "ride her own wave." Seeing this inspires Hinako pull herself out of her depression and decide to start training as a lifeguard.
- At the end of the movie, Hinako happens to be near the same Christmas date location that she'd once visited with Minato. While she is standing outside, the loudspeaker begins to play prerecorded message to her from Minato, causing her to break down into tears. It turns out that Minato recorded it almost a year ago, planning to take her to that location again as a date.
