I just marathoned Love Live! School Idol Project these past few weeks.
It's quite jarring to see why NicoMaki was popular in S1.
Then S2 piled all the subtext. Or should this be text? We still don't know the reason for this scene.
There's always a scene where they're just standing in close proximity to each other, or bickering, or having a warm moment. If you'd watch S2 without watching S1, you'd think these were childhood friends or something.
Watch the movie if you're still unconvinced.
It's not like I'm unconvinced.
It's just that between S1 and S2 there's this huge gap of development between Nico and Maki that went from somewhat friends to romantic bosom buddies.
I don't want to call it pandering, as I feel that has a negative connotation, but it was probably like the team going "oh NicoMaki is super popular so let's give the fans something to actually indulge in."
The entire Love Live! project or whatever started in like 2010. Season 1 came out in 2013. My understanding is that NicoMaki was popular before the anime came out. You have the manga (2012) where they interact a lot more and you also have the Mogyutto 'love' de Sekkinchū PV (https://vimeo.com/107368867) which came out in 2012, like 11 months before the anime, which has some NicoMaki scenes. Season 2 started April 2014 so they probably just made some changes.