It's the first movie in the mega-hit blockbuster Youkai Watch franchise. (Tomoko says its star has recently dimmed a little, but it's still big.) This film was Toho's best ever for advance ticket sales and it broke the Japanese box office record for an opening weekend. The previous record holder had been Ghibli, with Howl's Moving Castle. It was also the top-grossing Japanese film at the Japanese box office in 2015.
It's okay. It's amusing, but you'll probably be checking your watch here or there. It's got one meaningful character, frankly, and he doesn't show up for almost half an hour. He's not that great, but at least there's something to him. However it does have fart jokes, lots of action and a bouncy kids' movie watchability. Personally I think it's a fairly thin film underneath, but it's also so energetic and lively that it's doing a pretty good job of covering up that fact.
The most important thing, of course, is King Cream Soda. I love those guys. Apparently the English dub uses someone else to sing the opening theme, which is heresy, but the ending theme is King Cream Soda all the way.
Anyway, the plot! It begins with Keita Amano losing his Yokai Watch. (Yes, the title's second word is a noun. I'd always thought it was a verb.) When he wakes up, he can't see youkai any more and seems to have forgotten that they exist. However an insanely huge cat youkai reminds him and... it's time for the theme music!
After that: his family visits Granny. It seems that the baddies have changed history so that Keita's grandfather never invented the first youkai watch, so our heroes go back in time to fix history! Sixty years ago, it turns out that Young Grandad is a bit grumpy and has issues. He's in need of a Moral About Friends, but also more importantly he's obsessed with a 1950s superhero with a goofy signature pose. Grandad thinks it's awesome. Keita's going to have to do it too. Naturally his friends fall about laughing.
I'm not that wild about Grandad, but he does wake the film up a bit. He also improves Keita by giving him something to react to. (There are of course Keita's usual friends Whisper and Jibanyan and I quite like them, especially Whisper, but their comedy interactions are clearly well-worn and familiar.) As for the plot... well, I guess there must have been something. Not a lot lingered in the memory. I remember the fart jokes, which amused me. Apart from those, though, I mostly just remember individual characters. There's a Yoda-like character with Star Wars references, who gets Yoda dialogue in the English subtitles. There are also fun but cartoonish villains, whose boss ends up briefly getting some tragic backstory towards the end. I'm not sure why, though, since that comes from nowhere and goes nowhere.
Oh, and I liked Granny. She's not in it much, but she makes a difference.
Frankly, I think it's a fairly unremarkable movie that sold big because of its name. English speakers might find the English dub funnier, which I understand tries to punch things up a bit. However it's also pleasant, likeable and has some nice design. 1950s Japan is attractively realised, while youkai are always fun to look at. I like the one who's just a pair of legs. It's fast-moving, has lots of comedy business and clearly gave a lot of entertainment to a lot of children. I'd be willing to check out the other movies. Number 3 sounds particularly bonkers, being a blend of live-action and animation...