Looking for anime/videogame title?

All I know are what the characters look like, sadly. There's a group a few boys, of which #1 has a green hoodie with a minecraft-esque design, #2 wears orange clothes and has a paper covering his face, and #3 has blue hair, red glasses, and carries around a gun. I have a picture of #3 and have tried to reverse image search it, but nothing turns up. I also know that this group has been popular on pixiv in the past few months?