If you go by the show and PVs and manga and game and diaries, there's tons of evidence Nico is in love with Maki, but not so much that it's returned, though Maki seems to know how Nico feels. Nozomi was the only one who supported Nico before she joined MUs. So Maki's not the biggest obstacle to the ship, Eri is. The best time to ship these two: in the period before the show starts. Nico doesn't even know Maki, and Nozomi is pining away after Eri but nothing whatsoeer is going on, and Nozomi is mature enough to want something to be going on with someone.