There's no shortage of grievances for an axed manga. I really wanted to see the slowburn drawn out and watch them go through all manners of stupid situations. I loved the hypnosis arc and would've welcomed more weird round-about ways Nagi and Airi express their affection for each other. C'est la vie.
Personally, in situations like these, I've grown past the concept of "explicit confirmation" - considering the target audience, it is pretty redundant. Series is tagged yuri, Nagi explicitly has a crush on Airi, they live together post-timeskip, they say I love you to each other... I mean...