only half of his hair, and shimada's hair isn't really unique compared to other masuda's other hair designs
only for more unique hair (like aizawa's screw) , full hair, or two characters who are often together (like best friends/a couple),
this half hair backshot is pretty unfair of to say 'you missed shimada' when a random guy is also pretty likely
fair enough, though I didn't really mean "you missed Shimada" as a shot at anything more as a "hey I believe this is another cameo and that's cool, think you missed it"
And I'd argue it's not always with pretty unique hair, for example by association we know Okada's cameo in ch3 because of Mikan's distinctive hair next to him, or Sakurajima and Kousuke in ch6 because we see Nomiya is sat there too, or Takashi's cameo in ch8 thanks to Tanya-san being next to him.
I don't hold spotting them over anyone's heads, I just find them really neat, I read
Jitsu wa Watashi wa for the first time about a year ago, and when I have reread (well, have reread it many times) it after having read
Sakura Discord spotting the sporadic cameos always made me smile, and they were a highlight in ch40 of
Weekly Shonen Hachi that helped soften the blow of knowing the series was cut short and I was finishing it (among other cool things about how Masuda landed the axing of the story smoothly).
I am enjoying the silly coincidence driven slow burn romance between the two dense shy kids here, Hikoichi and Nayu are so sweet and I feel funnily represented by the group chat trio as an audience, but Masuda's cameos just feel like a nice gesture as someone who became a fan of his works.
on that note, to mention it's interesting that the Shima of this manga isn't the butt monkey but actually a smooth talker, while we got Yaabo as the butt monkey who doesn't follow after the previous ones in naming scheme, I feel like Masuda knew naming him Kiri
shima would make fans coming from his previous works tickle, he knows what he is doing as an author and sometimes the in your face humour makes his ability for subtlety go unnoticed.