Your Lie in April

Shigatsu wa Kimi no Uso (四月は君の嘘, Your Lie in April) is a Japanese manga series written and illustrated by Naoshi Arakawa. It was serialized in Kodansha's Monthly Shonen Magazine from 2011 to 2015 (with 11 volumes), and it also has a 22-episodes anime series in 2014-2015, an 2015 prequel OVA, a 2014 spinoff light novel, a 2016 live-action film, and a 2017 stage play.

Kousei "Human Metronome" Arima used to be a prodigy piano player, but at a very high cost: his mother Saki was extremely severe on him as he practiced, to the point of abusing him mentally and physically. When she died of illness, Kousei mentally collapsed. Two years after this, the 15-year-old Kousei hasn't played again and simply lives his life with his best friends, the prospective soccer player Ryouta Watari and his next-door neighbor Tsubaki Sawabe...

Enter Kaori Miyazono, a promising violinist with a very spirited attitude. She decides to bring Kousei back to the world of music via making him play again, but changing his once-mechanical approach to music into a more free-spirited one, which may mend the wounds in his heart. But Kaori has her own issues, especially concerning her health and something she said to Kousei...

Tropes used in Your Lie in April include:

Abusive Parents: Saki Arima mixes this with Education Mama. Subverted in that she did not start that way: she once was a very sweet mom, but became this after being diagnosed with her ultimately lethal illness and becoming desperate as a result.
Accidental Pervert: In the first chapter, Kousei ends up taking a photo of Kaori... when she is standing over a dome on a public park just when the wind lifts her skirt.
Book Ends: Chapter 10 begins and ends with characters piggybacking each other after one hurt his feet, but the situation is inverted: in the flashback in the beginning Tsubaki carries Kousei, in the end Kousei carries Tsubaki.
Broken Ace: Kousei, if only because he don't wants to play anymore at the start of the story, but still seems obsessed with songs.
Childhood Friends: Tsubaki, Kousei and Watari.
Elegant Classical Musician: Several cute teens who play instruments are seen here, starting with Kousei and Kaori. Kaori subverts it a bit because she's cute and plays the violin, but her musical style is more vivacious and cheery than it's normally associated to the trope.
Ill Girl:
- Saki Arima once was this, and died two years before the story began.
- Kaori also seems to have a bad health, as she carries lotsa pills in her bags and once in a while seems to have seizures. Her illness may or may not be the same that killed Saki, and it ultimately kills her too.
Love Dodecahedron: Between Kousei, Tsubaki, Kaori and Watari. Kousei likes Kaori but is sure that she prefers Watari, Tsubaki likes Kousei and both cares for Kaori and is jealous of her, Watari is the target of Kaori's love (only not) and yet it seems he'd rather see her with Kousei, and Kaori was always in love with Kousei, but lied about liking Watari (which is the titular "lie in April") for several reasons and didn't reveal her affection for Kousei until after her death, via her posthumous letter to him.
Maybe Magic, Maybe Mundane: Is Kousei and Kaori's final duet entirely in his head or did her departing spirit really appear? On one hand, she doesn't say anything aloud to him and he had spent several past episodes drilling into himself the need to properly harness his imagination to play well. On the other, the manga has Tsubaki seem to react when Kaori appears, implying something was somehow sensed. Ultimately, while nothing is confirmed either way, the event does serve to confirm for Kousei that she's gone.
Megane: Kousei is a cute boy who uses glasses.
My Beloved Smother: As Kousei explains in the first chapter, his mother Saki trated him very badly when he was a child to make him a great piano player.
OVA: Moments
Pervert Revenge Mode: Kaori gives Kousei a hell of a beating in chapter 1 for accidentally photographing her panties.
Reality Ensues:
- The series subjects Kousei to Amusing Injuries too often for some viewers' liking, but Saki hitting him hard enough to cause bleeding is treated with the dead seriousness it deserves.
- Just because your abuser dies or otherwise leaves your life doesn't mean that the trauma she caused disappears at the same time And There Was Much Rejoicing. Kousei is still struggling two years after Saki's passing.
- On the flipside, Saki may have been an abusive piece of shit, but she was still Kousei's mother, and the death of a parent can be badly traumatising. Kousei has little emotional support; friends, no matter how close, can only be so much help, and Kousei's father is away at work almost all the time while he has no siblings. Whatever one thinks of Kaori's methods, this rut wasn't something Kousei could have gotten out of by himself.
- Kaori is an Ill Girl with a terminal degenerative illness. Late in the series, some hope appears in the form of a high-risk surgery. You'd think that since she's the love interest and made a promise to play together with Kousei again, everyone is going to work out, right? It doesn't, because reality doesn't load the dice even though you check the boxes of narrative convention.
Sensitive Guy and Manly Man: Kousei and Watari.
Snow Means Death: The last time Kousei sees Kaori alive is on a snowy rooftop. Later, he visits her grave in the snow and gets a letter with her last words from her parents.
Training From Hell: What Kousei had to go through to become a great piano player, enduring physical and psychological abuse from his own mom.
Tomboy: Tsubaki
Tomboy and Girly Girl: Tsubaki and Kaori.
Unwitting Instigator of Doom: Hiroko believes herself to be this, because she was the one who encouraged Saki to make Kousei into a pianist.