Ok so all the problems with this post.
You might not consider Rin main, but everyone else does.
Tomoyo’s name is literally on one of the games, that’s pretty main.
It’s really weird to make a distinction between main/secondary for this really unimportant fact.
Good for you. Have a nice day. Watch episode 3.
Damn it key, you did it again. 
Episode 2 starts out with a similar formula to Episode 1, namely with Yuu traveling around with Nao to tell people to ‘shut up about and stop using your powers’. There are some enjoyable moments to be had in this episode, such as an entertaining demonstration of Joujirou’s half-baked teleportation ability, but like the first episode, my enjoyment of this episode is on and off.
The second half of this episode is more like Episode 5 of Angel Beats in that we hear about the lead girl’s backstory. Much like that episode, it does a decent job of explaining why Nao is so cold and serious all the time, and she actually has some enjoyable moments, too! Under the context of later episodes, it also partially explains her relationship with Shunsuke as well as some foreshadowing as to why everyone is a mutant. While this does lighten up my image of Nao a bit, it doesn’t really help with her current standing when it comes to my favorite characters in this show. (An interesting little thing I noted is that she rebukes Yuu for empathizing with her, which reminds me of when (Rewrite - Akane Spoilers) Akane rebuked Koutarou for choosing her over everyone else in her route, which I found to be a pretty nice meta joke. XD )
I would also like to briefly mention the ending theme, Yake Ochinai Tsubasa, which is a pretty nice piece. I kind of want to hear the full thing, wherever it is. :3
Overall, I’d say this episode is an improvement over the first one, although I probably would not have sat through it if I knew things would get better. On to Episode 6! 
Wait what?
Episodes 3, 4 and 5 were all filler and pointless in the scheme of things, clearly. Stupid creators adding all this pointless stuff, man. Where the feels at.
But episode 3 introduced Misa and Yusa. And the ending of the episode was sad if you realized the situation that the guy was put in.
I think you need to install a new sarcasm detector
Awesome episode, had a beautiful weaving of comedy and sadness throughout. The pacing was quick, but it felt like it flowed well and allowed for some good laughs and plot development with Nao’s brother. The archery plot was great for showing the teamwork that goes into stopping the abuse of powers, and showing how the student council operates.
I’m curious about the “trusted one” Nao keeps mentioning, and how he relates to the story. Also interested what powers Ayumi may have; they alluded to the possibility of her having some when they mentioned that normally both siblings have powers (something star related?).
On a side note, I’m finding the idea of this series quite similar to the X-men movie Logan that just came out.
(Logan spoilers) Logan has testing on child mutants by a government force in order to build super-soldiers for war purposes, similar to why Nao’s brother was tested on. The school Yuu is attending is similar to the idea of Eden in Logan: gather up all the mutants to build a safe haven for them. There’s even a guy like Caliban who can detect the presence of other mutants! 
