A boy arrives in purgatory after dying, where he is informed that in his past life he committed a terrible sin, and cannot be reincarnated until he can remember what it was. Until he does, he is placed in the body of a middle school student named Makoto who committed suicide three days ago, and is instructed to live the deceased boy’s life. New Makoto quickly becomes fed up with his host body's situation, as the boy doesn't have any friends, his family life is in shambles, and his mere presence makes everyone around him nervous. But giving up is not an option, and if the spirit ever wants to move on, he must adjust to Makoto's life and understand what happened in the past.
While Colorful is much more somber/serious than A Letter to Momo, both movies address death and its consequences with a lot of heart and a touch of the paranormal. I definitely think they'll appeal to the same audience.
Death and reincarnation are inescapable, but what happens in between? Without warning and without his memories, a boy who only recalls his last name - Otonashi - wakes up next to a girl named Yuri who offers him a gun and tells him to shoot an angel. Assuming it must be a misunderstanding, Otonashi is then almost killed by the angel and is drawn into Yuri's army to battle to delay the beginning of his next life. Immortality is within reach, but if Otonashi remembers how he died, will he keep fighting or allow himself to vanish?
If you liked Colorful, you may enjoy Angel Beats! because both shows deal with death and reincarnation.
However, Angel Beats! focuses more on fulfilling ones unfulfilled dream wihile Colorful deals with correcting the mistakes in the former life.
One day, Uehara Kouichi digs up a stone by the side of a river, and when it breaks in half he finds a fossil inside - or so he thinks. The fossil is actually a Kappa that was trapped in the earth hundreds of years ago; it is revived when Kouichi washes the stone. When his family allows Kouichi to keep the Kappa, much to his bratty little sister’s annoyance, he affectionately names it Coo. But even though the Uehara family helps Coo regain his strength, and even battle him in an odd sumo match, Coo longs to find more of his kind. However, after following a few leads on where they may find more Kappas, Coo becomes the centre of a media storm, turning his life upside down. Will Coo ever be able to escape the constant hounding of the press, and can he find his place in this new world?
Keiichi Hara's Colorful was one of my favorite anime films of the last few years, but don't overlook its predecessor, 2007's Summer Days With Coo. While it doesn't have the complexity of Colorful and the animation is clearly a couple of levels below, Hara packs the same narrative skill and unerring eye for family dynamics into both films.
Don't be fooled into thinking "Coo" is a light, cheery family film. It's a pretty dark story full of difficult themes and rather dim views of the human race. As is Hara's style, however, the movie is ultimately optimistic in its take on the ability of good people to affect good results. Clearly influenced by Miyazaki, "Coo" is less refined but more gritty than the master's films. Highly recommended.
As to "Colorful", it's quite simply one of the best theatrical anime of the last half-decade. This is a serious, thoughtful movie that pulls no punches - dealing with topics such as teenage suicide, enjo kosai, and bullying. Hara takes pains not to sugarcoat his hero into a sweet, lovable cherub - Makoto is a complicated, difficult teenager whose path to darkness is portrayed with startling realism. Yet ultimately, the film is life-affirming and hopeful in a thouroughly Buddhist way.
Natsume is lonely; he has an ability that separates him from others: he can see and interact with spirits. Soon, however, Natsume discovers that he’s not alone: his grandmother Reiko also had the gift. But things get hectic and possibly dangerous for Natsume when he finds out that he also inherited the 'Book of Friends', a book that contains the names of all the spirits Reiko defeated and subjugated. He finds himself hounded by his grandmother's underlings and, with the help of a 'cat' charm spirit, decides to free them from the Book's shackles, as well as protect the book from those who seek to misuse its power...
Lonely Kaoru Nishimi has lost count of how many times he has moved schools thanks to his father's naval career. Newly landed in Kyushu, he finds most of his classmates instantly antagonistic towards him and suspicious of his elite background. Only two other students seem not to mind who he is – the infamously abrasive Sentarou and the gentle Ritsuko. Unbeknownst to Kaoru they have a passion for jazz, and they're about to pull him out of his stiff, joyless world into theirs of loose, swinging self-expression. Through friendship and frustration, love and despair, Kaoru will learn that life has a wealth of experiences in store for him!
Kids on the Slope has a fair share of romance, but I think the most important part of the series is the friendship between the two male leads, Kaoru and Sentarou. Likewise, while Colorful isn't initially about friendship, the theme becomes very important later on.
There aren't that many series about the strength and importance of friendships between males, and Kids on the Slope and Colorful are both full of really excellent drama, (though their pacing is completely different), so if you liked one you should check the other out.