
For me, it was the childhood promised that confused me.

*promise. Stupid autocorrect.

Well it's not like the author gave us a proper foreshadowing: the traditional way to show an important but "unseen" is by showing their profile if not from the front, in the classic-manga-style eye-level angle that usually reaches up to the character's mouth (with everything else above being kept hidden) or even from a high-angle that shows a part of the character's face or profile, but certainly NOT just the back! During the conversation with his yakuza boss, that first introduced us to Adachi, the character of Adachi was only shown from a high-angle shot that only let us see the the back of his head, which (from a traditional use of "camera angles" in *manga*) usually implies that the character introduced is still an unimportant character, as they're NOT gonna play an important in the story.

And even when he first appeared in front of his childhood friends to introduce himself, the way the introduction was shown wasn't half as emphasized as Shinagawa's own... This author doesn't seem to have an accurate grasp of manga conventions, yet.
Sooo for like the first chpt i was confused in who the seme was, my dumbass didn't look carefully enough to the cover and just assumed it was the first guy who showed up, but once the second chpt came I came to realization that I mistook the seme