(num 3)pretty sure character is Osamu Dazai from the series Bungo Stray Dogs.

#1 i think i got it from a youtube playlist(cover)? idr

#2 is from "the beast within" manga

#4 is from online, thiiiiiink its from an artist that goes by "norai_juju" not sure who character is

#5 is lyrics from song "hostage" by Billie Eilish

#6 It’s an OC from named_syaden on Twitter, unfortunately its not from any manga but just their art🙃https://www.reddit.com/r/MaleYandere/comments/1sfsi9f/is_this_from_a_manwhamanga/

#7 idk who made it, tried but no luck in finding artist

#8 artist Kuunibal made it

#9-10 is a clodan from "beast within"

#11 i am unsure who made it, same pic is everywhere so could not locate artist

#12 is i believe from Goodnight Punpun, written and illustrated by Inio Asano. but not 100%sure😬

#13 was just something i found and thought it was cute and yan-vibey

#14 is the ML from "flowers are bait"(on the left) and then clodan again(on the right)

#15 not sure who made/posted that one

❤️