It's a Ghibli film, but not a fantasy. Everything in it is 100% real world, except for a few "blink and you'll miss them" moments that are also fictional in-universe and simply represent a story being written by one of the characters. Don't trust the lying Disney DVD cover, which is trying to give the impression that this story-within-a-story is the real film. If that's what you want, go watch The Cat Returns, which appears to be a sequel to that in-fiction story and starts both its Baron and Muta. That really is fantasy, whereas this is a coming-of-age story with some fifteen-year-olds. It's light and comfortable to watch, but of course our fifteen-year-olds are taking it all very seriously and the universe is co-operating with them. Shizuku's parents are startlingly open-minded and I'd have been less generous in their position, although admittedly it's clear to the family that Dad's not saying what he really wants. Similarly the nascent love triangles are treated with more gravitas than they deserve, while the film seems to have more faith than I do in the long-term prospects for marriage promises between two fifteen-year-olds.
That's all fine, though. They're fifteen. That's what it's like for them. Besides, the questions they're trying to answer are real ones, with life-long consequences. Go to high school, or commit yourself unilaterally to something vocational?
Shizuku is a bookworm and a bit of a slob. She's also curious about someone called Seiji Amasawa, who appears to have read all her library books before she did. She keeps seeing his name on their library cards. Meanwhile her friend Yuko has a problem, having received a love confession from Boy A even though she likes Boy B. Naturally all this film's teenagers are endearingly oblivious to the possibility that someone might like them, no matter how they feel about other people.
Incidentally, this is the only film ever directed by Yoshifumi Kondou. He'd been a rising star at Studio Ghibli and was expected to lead the next generation after Miyazaki and Takahata retired, but unfortunately he died of overwork in 1998, aged only 47. That's a national problem in Japan. They even have a word for it.
The film doesn't have much of a plot. It's about teenagers who are being told that they should be studying for their high school entrance exams. Should they? That's the mainstream course. That's what society expects, if you're going to get a normal job and have a normal life. However what if you need to write stories? What if you might not even stay in Japan? There's a little antiques shop that in any other Ghibli film would be magical and even here is very nearly so. It's run by a lovely gentleman of slightly mysterious age who keeps his own hours and doesn't seem particularly interested in actually selling any merchandise. The film's nice. Not brilliant, but nice. Beautiful but comparatively unobtrusive animation, understated in its storytelling and comfortable to watch. Don't expect it to make you leap out of your seat in astonishment, but it's pleasant.