I'll try to avoid spoilers as much as I can, but it's difficult to talk about what makes the Anime so great without going into at least a few spoilers. First off, let's talk about what Your Lie In April [YLIA] is broadly about. Arima Kosei used to play the piano as a child, but his Mother [who was unable to live up to her full potential, due to a terminal illness] placed unnaturally high levels of pressure and expectation on him to compete and do well with the instrument. Killing all the joy Kosei had watching his Mother play the piano as a child and enjoying playing it himself, he eventually forgot about the instrument and stopped playing all together. That was until he met Miyazono Kaori, a high-on-life blonde violinist who wishes for Kosei to play as her accompanist on stage.
Because of his history with the instrument and his Mother, Kosei has trouble adjusting to even hearing the notes anymore, let alone play them. Eventually through Kaori's understanding and support, he begins to overcome his problems, as she pulls him out of his comfort zone, and forces him to deal with his problems head on. The first act of the Anime is all about Kosei overcoming this fear of the piano that he's built up since his Mother passed away.
The second act shows Kosei's maturity as a pianist, with Kaori telling Kosei that every song she plays is about something or someone, and she plays it with purpose. He takes the same approach himself, leaving the robotic and artificial performances his Mother would force on him, and bringing his own passion and interpretation to the songs he plays. The second act concludes, with Kosei reaching his creative peak.
The third act is where Kaori tells him that she herself has a terminal illness. Reliving the trauma Kosei faced with his Mother dying, he has trouble bringing himself to keep playing the piano, and sees music as a form of bringing death and suffering into his world, rather than life and happiness. Eventually he comes around, and tries to keep a positive attitude towards music, as he takes everything Kaori has taught him into consideration, and plays his music for her, and in remembrance of what she meant to him. Taking her philosophy of "Who are you playing for today?", he carries Kaori's words with him into his future; wherever that may take him.
That's pretty much the overall plot, but you have rivalries with other pianists, teaching others to play along the way, a love triangle dynamic complicated with his best friend not being able to tell him how she feels about him, as he battles away in his triangle. His mother's childhood friend standing by his side as he confronts his issues with the piano and his Mother's past. There's a lot going on, so don't be fooled into thinking this is a simple slice of life Anime with the typical love dynamics going on, there's enough depth and variety on offer that all sorts of viewers are catered for.
With that complexity and variety, you would expect things to fall apart, pacing to be off, or simply the arrangement of scenes to be contradictory or worse, off-putting. Incredibly though, the Anime manages to switch between sadness and laughter, tension and excitement, despair and hope, at the drop of a hat. The creators pull off impressive feats of story telling and drama, by not only constantly changing the rules, but even the arena they're played in. Events and narrative can be turned on their head by a few words from a predominant character, expectations are thrown out of the window when a heart-wrenching and melancholy scene has brought you to your knees, only to be lifted up by unexpected comedy relief. It pulls you into a deep pit of swirling emotions that the characters are feeling, and just as you're about to drown in them and you take your last breath of air before becoming enveloped entirely, it plunges its hand in after you and rips you out it back onto the surface. It manages that all important dance of making it serious, but keeping it light; it avoids the melodrama. The comedy is worth the same weight in gold as the drama is. Some affairs are the typical 'character throws a book at the guy when he says something dumb', but they can be elaborate in nature as well, as the dialogue can turn those emotional scenes into something completely different.
Each episode pushes the narrative forward in meaningful ways, and character development is constant throughout. The entire series avoids 'filler' episodes, and doesn't deal with any fan service of any kind. The Anime is out there to deliver its message, and it stays focused all the way throughout. Early episodes hold little importance to begin with, at least within their own limitations and boundaries, but it's as you arrive towards the end that the earliest moments where they meet and bond, suddenly take on new meaning, and the ending of the series completely changes the light in which you view the opening on a second viewing. In that sense, this is definitely worth a second watch, as the entire plot changes with the knowledge you've gained in the ending.
Some might ask if you need to be a fan of music to appreciate this Anime. I would say that a musical background or some interest in music would add flavour to the context of the Anime, but in no way does the appeal of the Anime hinge and depend on that knowledge or interest being present. This is a story about people, and their interactions with each other first and foremost, it just happens to be through the lens of music. It could have been about friends who share an interest in video games, or making movies together, or playing football, the drama exists irrelevant of the context. I play both the Piano and the Guitar, and my appreciation of the Anime hasn't been game changing with those included, it was like the icing of the cake, or the cherry on top to be more accurate. Even though the entire story is dependant on that context for it to function, my point is you could replace it with anything and it would still work. It was probably important for it to be about music though, because music is a universal language we all speak, much like our emotions. So in that sense, you could say that anyone from any walk of life would be able to appreciate what is going on through the music, or at least be able to relate in the sense of how music has affected them in the past.
Because of that universal approach in both the context of the Anime [music] and the humility shown towards and through characters, this is an Anime anyone could sit down and watch. Musicians, lovers, parents, academics, social butterflies, people with troubled backgrounds, the entire Anime manages to cater for a variety of audiences, and in the case you manage to tick more than one box, you're in for a truly memorable experience. The 'slice of life' genre is known for catering to pretty much anyone, because everyone has the common experiences of things such as school, friendship, love, and work. YLIA doesn't stop at the foundations of the genre however, and continues to build on top of them, and exceeds expectations regularly throughout, as well as turning them on their head for unexpected and memorable moments.
Excellent pacing, great writing, likeable characters, and interesting narrative. The ending takes the entire Anime, and elevates every section because of this new-found understanding of the characters and their motives. If you enjoyed similar things such as Clannad, Welcome to the NHK, Nagi No Asukara, Kids on the Slope, then you'll love Your Lie in April.
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