To put it into perspective: Cinemas in Japan are chill, it’s not like American or “Western” cinemas where people shout aloud at hyped scenes or laugh so loud where you can’t even hear what the dialog is or talk amongst themselves causing distractions (or yet, using their phone at max brightness that becomes distracting towards other viewers).
Instead: it’s more on immersing to a movie at your own desire, everyone for the most part is dead silent because they know that they are inside a cinema as courtesy is considered, while I’ve heard that is starting or has already started to decline in the US (& Western nations) since the experience of being in a theater isn’t the same as it used to be.
Like most answers about the US, it depends on a lot, we’re a big place. As someone who is at the movies 3-4 times a month I’ll say the biggest factors that contribute are
I typically go during the week after work and generally wait a bit to see new releases and I usually have a couple other people with me in the theater and they’re usually chill. If you go opening weekend to a new movie in a crowded theater then I’d say you can pretty reliably count on a few people making quietish comments and a few people checking their/phones a few times. I also find if you tell people to shut up or put their phones away they usually listen. I’ll also say if you’re going to see the new prestige A24 drama expect less interruptions than say The Super Mario Galaxy movie or The Minecraft Movie