There's a scene where the main character squeezes the cat really hard in anger and refuses to let go even as he's telling her it's hurting him and begging her to stop. She nearly throws him, too, but stops herself right before actually doing it and just drops him on the ground instead. She then tells him she doesn't love him, which makes him very sad and revert back to a thin, malnourished state, though he recovers later. She is very mean to the cat and never apologizes.
There are butterflies shown a few times. The main villain is also referred to as a worm, though it doesn't actually look buglike imo, it's just a really abstract-looking god
The main character, a 17-year old girl, is in love with a guy in his final year of grad school. Her crush on him is a very central part of the movie. I'd say it's kept vague whether or not the guy reciprocates her feelings, but... this movie very much has romantic tones imo. He doesn't *not* reciprocate her, either.
One instance where a cat & the main character are running through traffic, there's a lot of honking and tires screeching during that sequence. And then another instance where they almost crash their car into an oncoming vehicle, but manage to swerve away in time.
Multiple moments where blood is shown: Souta gets an arm injury in the beginning, and then later on, you can see blood on Suzume's feet, and also going down the drain when she washes it off. Nothing too bad.