[Used Can]

^To be fair, Rito was never too interested in Lala. Sure, he grew to like her, but by the end of the first series it was still clear no girl made his heart race as hard as Haruna did.
By the end of the first series, had Rito managed to confess to Haruna, she'd likely had done so as well, and that'd have been where it ended, because neither of them would have likely been keen on the idea of a threesome even less a harem. They would have been together, and TLR would have been over, unless we'd have got an AU-spinoff or and spinoff with a new MC.

The issue in the series, so far, has been that if we assume the author plans on having Rito end up with someone other than Haruna, or aiming to build a harem, we're yet to see any actual change in Rito's mentality would point into that direction. At best, we've had scenes in which girls like Lala, Run or Momo have made his heart race for a bit, but we're yet to see any reaction from him that suggests he might have started reconsidering his feelings for Haruna, or that he's started falling for some other girl more, or that he wants a harem.
As of yet, as far as we know, Haruna still is the girl he likes the most.

So, Rito has made no progress with Haruna, because that'd be an end game. Yet, at the same time, even if we say that in Darkness more girls have fallen for him and that girls that were already in love with him have fallen even harder for him, as far as Rito is concerned, we've hardly seen much development, or at least, a development that actually has an effect on the plot and moves things in different directions.

I've been enjoying Darkness a lot, easily much more than the first manga, but it's clear as day that they're dragging things as much as they can, and in the previous manga that led to a stale story, with only entertaining chapters every now and then.
So, I'm hoping Hasemi decides on a path already and develop the story into it - be it a single girl path or an actual harem path, I want to start seeing developments that actually takes us into that direction.