Forest of Piano (JP: Piano no Mori ~The Perfect World of Kai~) is a Seinen manga by Makoto Isshi, which was serialized in Young Magazine Uppers and Weekly Morning from 1998 to 2015 and compiled into 26 volumes.
It was adapted by Madhouse in 2007 as an animated film, covering a majority of the childhood arc up until the end of the concours.
A 2018 anime adaptation, in the form of a series, was produced by Fukushima Gainax. Two seasons have been produced thus far; both are available on Netflix.
This series provides examples of:
- Affectionate Nickname: Kai found Takako crying in a bathroom urinal during the Japan national piano competition. After cheering her up, he starts calling her the "Toilet Princess". Later Shuhei also calls her that.
- Bowdlerize: The exact natures of Rei's profession and the Edge of the Forest itself are obscured in the animated film adaptation. Savvy enough viewers may infer from life experience and figure it out immediately. More innocent viewers, however, can easily mistake the Edge of the Forest as merely the town's slums and Rei's job as that of some sort of bar hostess, as opposed to what they are explicitly stated to be in the original work (i.e. the town's Red Light District and a prostitute, respectively).
- In the Netflix anime, Rei is stated to be a prostitute, with even Kai recognizing this fact.
- Dark and Troubled Past: Wei Pan: born to a Chinese mother and a unknown foreign father, he was doomed the moment he was born. He was viewed as a "bomb" because of his mixed heritage and his poor background. Later, a wealthy business man bought Wei, still a young child, from his mother. Wei's new father adopted him only to lock him away to cultivate his ability to play piano. Forced to watch multiple piano videos for practice, Wei only found solace listening to Ajino's piano and did his best to copy and impress him. His upbringing is reflected in his piano, showing his abusive past. During the competition finals, Wei finally manages to break away from his bleak outlook and wins second.
- Fat Bastard: Kinpira.
- Cynic–Idealist Duo: Wei Pan acts as Foil for Kai. Both came from very poor backgrounds and both used Ajino as inspiration. The main difference is Kai had love and support from his mother, Ajino, Shuhei and other friends, while Wei was adopted by an Abusive Parent who only adopted Wei to have Wei become The Ace at playing piano, not caring for his well-being. As such, while Kai's piano is uplifting, Wei's piano is darker. If not for his support group, Kai could easily have turned out like Wei.
- Dude Looks Like a Lady: Kai has taken much of his looks from his mother. So much so that the dorm manager mistook Kai for a girl, not realizing until she gave him a dress and Ajino had to point it out for her.
- An adult Kai takes advantage of this and moonlights as Maria, in order to avoid the competition rules that they can't perform leading up to the competition. Saga also falls for it, giving her flowers multiple times, and does not find out it was Kai until years later, much to his (Saga's) embarrassment. He had no regrets though.
- Friendly Rival: Kai and Shuhei. Later on during the Chopin Competition, Kai and Lech also qualify.
- Friendship-Straining Competition: Happens between Shuhei and Kai during the Chopin Competition, though it is more one sided on Shuhei's side. Kai still considers Shuhei a close friend, while Shuhei, due to prompting by his father, briefly loathes Kai due to jealously though they later reconnect.
- Generation Xerox: Shuhei acts as the Unknown Rival to Kai, much like how his father developed the same dynamic toward Ajino, who also mentors Kai.
- Gratuitous Foreign Language: In Poland, during the Chopin competion, characters often speak Polish to each other but only as phrases they picked up. Even the Polish judges don't speak Polish in scenes where only they appear. However, in certain celebratory scenes the Polish "Sto Lat" song is played in the background.
- Hooker with a Heart of Gold: Reiko (Kai's mother) is a prostitute. She is also a wonderful mother who gives Kai unconditional love.
- I Let Gwen Stacy Die: For Lech it is more accurately "I let my sister fall into a coma". Both Lech and his sister Emilia played piano. When they were younger, Emilia left ahead of Lech to practice only for the bus she was on to crash, putting her in a coma for years. Subsequently, Lech played out of guilt, hoping his piano playing will eventually wake his sister up. After the Chopin Competition, she does.
- Informed Ability: The character's reactions to, and descriptions of, the piano playing in the anime have virtually nothing to do with the actual music shown.
- Jerkass: Daigaku Kanehira, otherwise known as Kinpira, is a child who constantly bullies Shuhei and Kei throughout the childhood arc.
- Market-Based Title: The anime film is sometimes known as The Piano Forest.
- Maybe Magic, Maybe Mundane: The Forest Piano stays in marvelous condition despite being left outside in a forest all the time, and it only plays music for Kai. It's never made clear whether this is actually magical, or if Kai is just playing it differently (perhaps by hitting the keys harder than everyone else).
- Lech hears the voice of his coma-bound sister. At one point he also appears to hear the thoughts of the orchestra director during his final performance. It's never made clear whether this is actually psychic/magical, or if he's just imagining things.
- Meaningful Name: Kai full name written in Eastern order, Ichinose Kai, is a pun for "ichi no sekai," which roughly translates to "#1 of the world."
- Performance Anxiety: Aside from some of the background characters, Takako suffers through this before her performance in the South Central district preliminaries for Japan's national piano competition, which had been exacerbated by Shuhei's presence. Kai helps her through it.
- Pragmatic Adaptation: The animated film takes steps to ensure that it works as a self-contained story by taking out elements that lead into the story past the Time Skip.
- Pretty Boy: Kai looks like a traditional Bishōnen archetype, as does Lech. Especially Kai, since when dressed as a woman everyone comments on "her" looks.
- Red Light District: Kai lives here. It's nicknamed "The Edge of the Forest" for its location in the city and is known for being a Yakuza lair.
- Red Oni, Blue Oni: Shuhei and Kai. Shuhei is usually very calm and composed, has had the best training his parents could afford but is conflicted about living up to his father's expectations of him. Kai is more carefree and spirited, has a natural talent for piano but no formal training until meeting Ajino. He plays for the enjoyment of playing piano and becoming a worthy pianist.
- Satellite Love Interest: It's as if Sae exists almost exclusively for Kai to have someone to relate to and to be his girlfriend, since she doesn't have any plot relevance past the chapters that lead to them hooking up.
- Single Mom Stripper: ...Well, prostitute, anyway. Reiko.
- Son of a Whore: Kai's mother, Reiko, is a prostitute of his town's Red Light District. Notably, Kai has zero angst about this. He keeps his background secret, but he's not remotely ashamed of it.
- Surprisingly Realistic Outcome: Kai's first attempt in participating in a piano competition ends with him getting eliminated in the preliminaries. Not for lack of skill on his part, but because his poor-etiquette angered the majority of the judges.
- Sweet on Polly Oliver: Saga toward Maria, Kai's cross-dressing disguise for the P-Club.
- Technician Versus Performer: One of the central themes of this work. In this case, both schools of thought are exemplified through the two leads. Shuhei is the Technician and Kai is the Performer.
- Time Skip: One spanning several years occurs after Shuhei moves away and the piano of the forest is destroyed by lightning and a forest fire.
- Unknown Rival: Shuhei has a massive inferiority complex and considers Kai his greatest rival, despite how the music world has initially judged their respective skills. Kai, on the other hand, only sees Shuhei as his best friend and is perplexed whenever the former treats him like an opponent.
- Victorious Loser: More or less, everyone who is not Kai.
- Shuhei is disqualified from the Chopin Competition early, but it allows him to develop his own piano and his own self-worth, and not having to live under his father's shadow.
- Lech, during his performance, understands it was not his fault his sister fell into a coma. He wins third place.
- Wei Pan, also learns of his own self-worth during his final performance, allowing him to move beyond his dark and troubled past. He wins second place.
- Kai also qualifies for this in the first half of the series. He lost his first competition but realizes he simply must become better to win future ones.
- Unbalanced By Rival's Kid: Shuhei's father ends up projecting his own conflicted feelings towards Ajino onto Shuhei and Kai. Shuhei, who is already suffering from a mountain load of anxiety, gets it drilled into his head that he needs to surpass Kai to truly become successful, leading to Shuhei's own resentment towards Kai. It's only chapter the Chopin Competition that Amamiya Sr. realizes what a negative impact his parenting has had on Shuhei.
- Unskilled, but Strong: Kai ended being an interesting variant of this as he's a natural prodigy at playing piano, but because he got his start literally playing a broken piano in the forest, he had a bit of a learning curve to adjust to playing a normal piano. Not to mention in his first-ever competition he lacked the etiquette expected of the performers. This factor ticks off most of the judges to the point that Kai gets eliminated in the preliminaries.
