The story of Sekai de Ichiban Utsukushii begins with our protagonists, Shimazaki Toru (Tsubaki Taiga) and Setta Fumihiko (Yokohara Yuki), making plans after school. Shimazaki describes himself as a busy eight year old because of his piano lessons that have him practicing after school from Thursday to Friday. Because it’s Wednesday, the two are able to hang out and spend time together. On their way to Shimazaki’s house after school, the pair buy trading cards for a series called Ultra 7 in hopes of getting their favorite character: Eleking!
One mystery card is five yen, and the boys buy two each. Shimazaki pays with a hundred yen coin, and the old shopkeeper gives him his change, meanwhile Setta pays with a thousand yen bill which shocks Shimazaki. Setta tucks his change purse and trading cards under his arms in order to receive all of his change and struggles to put it away. Shimazaki leaps to his rescue, helping Setta put away all of his money, and, with the power of quick math, realizes Setta is short fifty yen! Setta doesn’t seem to be able to count, so he didn’t notice.
As dramatic as two eight-year-olds can be, Shimazaki asks the old shopkeeper for the correct change which leads to a hilarious exchange as the lighting on stage turns blue and terrifying. The old woman quickly finds the missing fifty yen on the ground. Little Setta dropped it because of his tiny hands.
The boys run off and open their mystery trading cards. The first three are failures, but the last is a success! Shimazaki pulls Eleking out of the sleeve and gifts the card to Setta. Once they’re at Shimazaki’s house, he goes to practice the piano. He is supposed to practice a little bit every day even if his lessons aren’t until tomorrow and Friday. Setta becomes absolutely entranced by the piano and keeps asking for Shimazaki to play the song until he’s heard it three times. After being asked if he wants to try playing the piano, Setta replicates the song he heard perfectly, if not a bit more quietly than Shimazaki’s own playing.
Shimazaki immediately becomes angry, not understanding how Setta can play a song he’s been struggling to get the tempo right. He believes this is a big joke, but he slowly comes around once Setta proves he can’t read music nor does his family own a piano. His “super power” is that once he’s heard something three times, he can do it. Trusting his friend, Shimazaki plays a few songs three times, so Setta can play them as well. The two develop a bond over their shared love of music.
But Setta’s love is far more obsessive. As the boys age and go from eight-year-olds to fifth graders, the only thing Setta does is play the piano. Whenever Shimazaki comes over to Setta’s home, all he is doing is playing the piano, something his parents bought for him. One of their classmates, Sawaguchi Mari, doesn’t understand why the two are friends, but Shimazaki defends his friendship with Setta. The two will be going to different middle schools in a year, and he wants to spend as much time as he can with Setta.
Sawaguchi and Shimazaki part ways after saying they’ll be attending the same middle school next year, and Sawaguchi gives him a bracelet. Later, Shimazaki receives a letter from her in which she confesses her love to him, and he breaks down crying. Setta admits to him that he’s never been smart and has always heard how he isn’t from his parents and older brother.
In his middle school and high school years, Shimazaki picks up the cello and drops playing the piano. This is due to his grandfather. Shimazaki chose the cello because his family is full of pianists and violinist, so he wanted to add something new. Despite this, his friendship with Setta hasn’t changed. Setta is still absolutely entranced by the cello and attempts to have Shimazaki replicate the notes from the piano on the cello. These notes are far too low at first, but Setta picks one that Shimazaki is able to play. The power of music is still strong in their hearts despite not playing the same instrument anymore, and they want to create music together.
Shimazaki’s story jumps to when he’s a university student as a music school. His love of music has deteriorated, and his professor confronts him, wondering about his love of music and if he can feel it within his heart. The conversation does not spark joy in Shimazaki but actually has the opposite effect. He yells how he is going to give up on music.
Walking along the road next to the beach, a familiar voice calls out to him, and it’s university aged Setta, who is now wearing glasses. The two chat about music and how Setta recognized him from so far away. Setta admits its because of Shimazaki’s cello. During their conversation Shimazaki admits that he quit music and is transferring to a non-music university. Meanwhile Setta hasn’t been in university but has been studying music at Eglantina, a restaurant. He convinces Shimazaki to come with him to the restaurant to chat more.
At the restaurant, they meet Kase Yasushi, the owner of Eglantina, who Setta has a strong affection for and hugs despite Kase’s annoyance at Setta. The talented musician always called Kase by his name instead of the proper title “Master,” as he is the owner. Setta plays the piano while Kase and Shimazaki talk about Setta. Setta apparently showed up at the restaurant one day asking if he could play the piano there because he didn’t have a piano at home. This shocks Shimazaki because the last he knew, the household had one.
Him and Setta sit down to drink, and the two chat about their lives. Setta’s family have pressured him to go to university, but he can’t because he’s never been smart enough. His brother got into Toudai and I believe that’s why the piano was sold? So his brother could study in peace, but Setta is fine with it because he became friends with Kase in the end. Shimazaki thinks Setta has a good life with friends, and Setta admits he probably would be dead if he didn’t have friends. The two drink together and end up at their old elementary school and sing the school song in the darkness of the night until they’re yelled at for being too loud.
Shimazaki graduates from university, and they hold a celebration at Eglantina. Kase invites a rich business owner and his part-time staff, Nagasawa Koumi, to join them. Both are fans of Setta’s music, and Setta seems embarrassed when Nagasawa compliments him. Kase asks Setta about a certain type of music which turns into a lesson about tango. Shimazaki and Setta end up talking because Setta is writing music now but doesn’t have a teacher or lessons to help grow. Shimazaki runs off because he has an idea and Setta follows him.
Shimazaki takes Setta to his old piano teacher, Kitajima Reiko, who he hasn’t been to since high school or so. Setta brings all the music he’s been writing, and she’s shocked by the sheer amount. She plays one of Setta’s songs and doesn’t think it’s bad. Kitajima gives advice on how to make it better, and Setta immediately goes to work on it. He greatly improves the piece in a short amount of time and looks forward to their next lesson. She ends up giving Shimazaki the money back for Setta’s first lesson because she doesn’t need it.
The song Setta creates is absolutely beautiful, and Shimazaki laments about how much talent Setta has and how it has far exceeded his own. All of the usuals in the restaurant think Setta’s song is wonderful, and he starts talking about the things he wants to do. Shimazaki thinks he needs a sponsor for his music, and the rich business owner immediately jumps in to say he will fund Setta’s work. He also has an idea of where they can perform the new piece. Enoshima has a festival or the like coming up, and Setta’s work can be done at the opening ceremony. The patrons recommend what his next big thing should be, but Setta has already decided: he wants to create an opera.
Shimazaki is the only one who thinks it’s not a good idea, but every member of the bar, as well as Setta, wear him down until he agrees to write the story. Setta recommends it has a kaiju, or monster, in it as well as romance. Although Shimazaki isn’t thrilled with the ideas Setta throws out, he creates a story which Setta loves. The restaurant patrons love it, and they decide the parts. Shimazaki and Nagasawa will play the lovers, Kitajima plays the goddess who sings the final aria, the business owner will play the old woman, and Kase is stuck playing the kaiju. Setta can’t play any role because the music is difficult, and he’s needed to conduct and play the piano at parts.
I didn’t catch much of the story of the opera if I’m honest. Shimazaki and Nagasawa’s characters go to Inamuragasaki and encounter the legend of a monster that lives there. They get drinks from an old lady who gives Shimazaki the wrong one and also gives them wrong change, something that’s mimicked from early on in the story. She talks about why and summons the kaiju who has some kind of family connection to Nagasawa’s character. He fights Shimazaki’s character, who is hurt, but Kitajima’s goddess comes and gives Shimazaki a sword to fight the kaiju. Shimazaki wins and spares the kaiju’s life and keeps the sword.
During all of this, Setta is conducting the opera while getting distracted. His love for Nagasawa as she sings her first solo is fully visible as he watches her sing and tries to follow her before realizing he’s supposed to be conducting. He also gives her support during one of Shimazaki’s solos. There are parts where he sits on the piano bench and watches the fight in excitement before realizing he’s supposed to be conducting.
The performance is a success, and, back at Eglantina, Setta seems a bit down. Shimazaki wants to know what’s wrong, but Setta makes him promise not to tell anyone, even Kase, who is in the restaurant and can clearly hear their conversation. He asks Shimazaki if he’s ever been in love. To which Shimazaki says no, but Setta says he’s a liar because he remembers Shimazaki had a crush on Sawaguchi when they were kids.
Setta admits he’s in love, and Shimazaki and Kase immediately know it’s Nagasawa. Setta doesn’t understand how they figured it out, but both say it was obvious how he was acting at the opera. Shimazaki asks what the two have talked about alone and what follows is a cute conversation about how the weather is hot and refuses to become fall. Shimazaki convinces him to confess while the pair go on a walk, but Setta is worried about what would happen if Nagasawa doesn’t reciprocate his feelings. Shimazaki doesn’t have an answer for that.
Nagasawa comes to the restaurant and her and Setta sit at a table awkwardly until he stands up and shouts, “LET’S GO ON A WALK,” which shocks Shimazaki and Kase for how quickly he asked. Nagasawa doesn’t seem to mind and agrees. The two go out, and Setta admits his feelings and Nagasawa has the same ones. She likes Setta too and admits she loves the music he creates as well as who he is as a person. She thinks he’s the most beautiful person in the world.
The two talk more about their feelings, and Nagasawa admits she wants to have sex with Setta but doesn’t know if that’s something Setta wants. He admits that he does, and she works out that Setta hasn’t done anything like that before. He’s a bit embarrassed but she is as well. Nagasawa was in a previous relationship where she has had sex, but it doesn’t seem to be the best experience for her. Setta is flustered, but the pair share their first kiss because of Nagasawa leaning in, and Nagasawa reassures him that he is still the most beautiful to her. The pair kiss again, this time Setta is the one to initiate it.
Kitajima rushes into the bar looking for Setta. He’s canceled all of his lessons, and she’s trying to find him to understand why. Setta comes in with Nagasawa and admits his father doesn’t want him to play music anymore. He’s invited his brother to come and listen to him play for his final performance before he has to give it up. Setta’s brother comes in and listens to his brother’s song. After, he talks about how beautiful the piece is and how his brother was growing up. He sees how the people around Setta have cultivated him into being a wonderful person and musician and gives his blessing for Setta to continue creating music. The Eglantina family share a tender moment together.
On another day, Setta has a surprise for Kase. Him and Nagasawa play a tango which makes the older man so happy. The restaurant gets a mysterious and dark patron walk in as Nagasawa keeps messing up the tempo. She asks Kase to take her to a music shop, so she can buy a metronome to practice playing the piano. Shimazaki tags along, and Setta is asked to look after the new patron. He makes the man a drink before asking if he can play the piano. The man doesn’t seem to care, and Setta sits down to play.
An indiscriminate time passes before the man stands up, a bit of rage on his expression as he starts stalking towards Setta until the trio return with the metronome. They had to go all the way to Yokohama to get it, and it takes a bit of fiddling before Setta gets it to work correctly. He sits down to practice more with Nagasawa but she’s called away to help Kase. She ends up getting caught by the man, and it’s revealed the two know each other. This is her ex-boyfriend, Tsutsumi Kantaro, and he doesn’t like that she’s moved on from him. The two get heated, and Kase steps in and learns about their past. Kantaro pays for his drink and leaves.
Another day, Kantaro is back, and Kase does everything to keep Nagasawa and him apart. Setta comes in and thanks his friends for gathering. He’s going to be 30 soon and has been coming to Eglantina for about ten years now. He’s finally written a tango for Kase, who is ecstatic. As Setta plays, Nagasawa and her ex argue, Kase keeping a close eye on the pair. When Nagasawa says Setta is the person she loves the most in the world, Kantaro flips out. He overturns tables and confronts Setta in an argument. All of the patrons try to keep the pair apart, and Nagasawa doesn’t want Setta anywhere close to her ex. At the same time, Setta doesn’t seem to understand the danger he’s in. The crazy ex pushes everyone off of him until he goes to Setta and stabs him in the stomach with a knife.
Shimazaki tackles Kantaro, and Kase gets the knife out of his grip. Setta has already lost a lot of blood, but he still has the energy to say Kantaro is a horrible person. He gets the inspiration to write a new song from this moment and thinks he’s able to write. He slowly makes his way to the piano as Kitajima is calling an ambulance, and his friends look on with pleading expressions for him to stop. Setta’s vision is changing and asks if Nagasawa can see the same things. Setta gets to the piano bench and as he places his hands on the keys, he collapses. Shimazaki sprints across the room, shouting Setta’s name and clutching onto his limp body as Kantaro cackles.
Setta’s four friends attend his funeral, the music teacher bringing beautiful white flowers to place upon the piano. The four reminisce about Setta and everything he’s done. I believe Shimazaki points out the date of Setta’s death coincides with the death of Franz Schubert, an Austrian composer, to which the pair also share initials. Setta’s ghost visits them one last time before the play comes to an end, the stage lights bright on the pure white flowers before going dark.