You are the Silent Protagonist. You talk to girls, but they're the only people who can hear it. The camera shows us your point of view, except when it doesn't. You exist in three incompatible continuities (or five if you include Season 1), each of which effectively contains only one other human. She'll be the only person we see and hear. This show is thus effectively a series of one-woman plays. You could perform them on stage with a bit of tweaking, or even radio.
They're also a bit dark. Every one will be exploring some kind of problem or unhappiness of their focus girl, even as we assume it's heading for a happy ending. Personally I found them rather good, which feels like a slightly brave thing to say of a show that's blatantly an anime relationship substitute for otaku who desperately need to get out of the house and try talking to people rather than pixels.
EPISODES 0-4: HANASAKI YUI
The only returnee from Season 1, making her the veteran of approximately ten episodes. (They're tiny episodes, admittedly, but that's still a lot. The norm is four. She's in eps.1-4 of both seasons, plus a third of an OVA and the recap-a-thon that is Season 2 ep.0.)
What's interesting about Yui is that her story seemed to have ended. She had her school exam troubles. You helped them get over them. You became her boyfriend. These episodes aren't undoing that, but instead are exploring what happens next... which for my money is an interesting, significant extension of Yui's story. You're already dating before this season starts. You go to the beach together. You seem like a nice couple.
Unfortunately it soon turns out that you want sex. Yui's not ready and indeed is a bit scared of that. (Interestingly, it's possible that the creepy male gaze of Season 1 is being used deliberately here, in an ep.1 shot where you ignore the photo Yui's hold up and instead just look at her chest. Looking back after I've finished the show, I think this really was reflecting what was on Silent Protagonist's mind.)
Things turn awkward.
Yui becomes insecure and more upset than she looks, which is saying a lot since she's not exactly hiding it. I think it's quite a well told little examination of a relationship stage that normally doesn't get much fictional examination.
EPISODES 5-8: NANAHASHI MINORI
She looks young. She's younger than you, anyway. I think she's in high school, while you're a student who's working part-time at her family's bathhouse in return for being allowed to stay there. Minori's flirty, funny and very aware that the bathhouse isn't getting enough customers these days.
It used to be different. It's been around for ages. It was around during the war, when people who'd been bombed out of house and home used to come there to forget their troubles for an hour. It used to be part of the local community... but the community itself is disappearing. That's a thing in Japan. Demographic change is hollowing out rural areas. This is also demonstrated when Minori invites you to a festival and starts explaining how it used to be so much busier and more entertaining. "It's a bit lonely when the things around you change."
She's not a negative person, mind you. She's a live spark. However she's in danger of losing her home, her identity and the place that she'd wanted to make her future. "They had career counselling at school."
I liked this too. Minori's the non-sibling counterpart of Season 1's Momohara Natsuki, i.e. less creepy. She's just as much fun, though.
EPISODES 9-12: AMATSUKI MASHIRO
Amatsuki made me laugh. She decides on sight that you're up to no good and thereafter calls you Mr Pervert. "Why? Because you took my picture yesterday and now you're stalking me. It's none of your business, Mr Pervert." When she eventually switches to a more conventional form of address, (a) this is a big deal, and (b) you'll ask her to stop because you're not used to it.
This is especially funny when she's being relaxed and natural, but still using a form of address that suggests you deserve to be arrested. "Mr Pervert, I want you to come to my room."
Anyway, Amatsuki's problem is that she's a gymnast who got injured and can't find alternative employment. She keeps taking job interviews, but always fails them. You suggest that she practice with you. (Her response is, "Practice at being a pervert?") Amatsuki's funny, but she's also not very good at ordinary things and she's getting a bit depressed about it.
This is another good story. It's not surprising, but it's witty and again Amatsuki feels real.
Overall, I'd call this an underrated series. I'm sure most people steered clear of it because of what it is, while most of the remainder will have been frightened off by the creepy bits in Season 1. (That's a lot better this year, for what it's worth. You may or may not view this as an improvement, though, because it was very funny to watch Season 1 being unintentionally creepy.) This is another genuinely worthwhile batch of short character studies. I'm hoping for a Season 3.