I don't really think it was a 180 change, but rather a matter of Azuma not even considering the possibility of having romantic feelings for Makoto due to their work dynamic (as well as the president putting so much responsibility on him to "protect" Makoto from anyone who might look at Makoto with impure thoughts). Like, he's technically "kissing" Makoto over and over, and inviting him into his home and to all his favorite places that he's never shared with anyone else. He even deliberately interrupts that other co-worker's confession to Makoto (though we only later learn that he did it on purpose).
Only when Makoto confesses and Azuma turns him down because "I'm not good enough for you" does Azuma realize that maybe he does actually have feelings for Makoto as well, even thinking "Why does it feel like I'm the one who had his heart broken?" because the yearning that he's been subconsciously harboring all along has been wounded. Of course Azuma might not feel as strongly about Makoto as Makoto feels about him, because it's a new realization on his behalf, but still, I wouldn't say it's a 180 change.
Omg thank you for this!! It makes sense now
So he actually had feelings? for makoto right from the beginning but it was overshadowed by the pressure of responsibility sort of
It's hard to say if he had feelings from the very beginning of the story, but I'd say by the end of the first volume (ch. 6), there was definitely something going on, because Azuma was acting sort of jealous over how well Makoto got along with his ex-coworker, and then Azuma kissed him while he was sleeping, thinking it'd break the curse, even though he could've just talked to Makoto about it first and tried it out when Makoto was awake. I thnk that's the starting point of Azuma falling for him more and more, even if he doesn't realize it until the confession at the end of volume 2~~
At least that's my interpretation!^^
The 180 change in azuma. When did he fall in love