Jujutsu Kaisen - Ch. 258 - Inhuman Makyo Shinjuku Showdown, Part 30

[NotSomeone]

I know you guys like to use this term, but you have to udnerstand it to use it properly. Chekov's gun is a type of story with no loose ends. Where every situation is essential to the story. But here we have just situations that may or may not be used by Gege later on but some of them are left behind.

For example:

American army which appeared for like 2 chapters? got wiped out and never got mentioned again. And there was no consequence of that nor reaction of USA for it.

Or filler character Kashimo, which appeared only to get beaten TWICE and had zero impact on the plot.

A Chekov's gun is not a "type of story", it's a device.
A story could have both a chekov's gun in it and a loose end.
Take early James Bond movies in account, the gadgets he uses are chekov's guns. Q explain them, what they do, and later in the movie they come in clutch to take Bond out of a tight spot. But you wouldn't call these movies without loose ends or anything like that.

Earlier I said that the manga has many of those: Elements that are explained and set up to be fired up later in the story, not that all of these introduced things are used.