It's a fairly unremarkable magical girl anime. It's not kiddified enough to suggest that it was made for tiny children (and it was broadcast at 10pm on Fridays), but at the same time you needn't expect adult storytelling, darkness or the grim despair that's become normal in shows like Madoka Magica, Yuki Yuna, Magical Girl Raising Project, etc. It's only got the faintest hints of that genre, e.g. baddies apparently getting killed and the girls using weapons instead of magic. The show's full of cliches and doesn't care who knows it. There are cheesy villains. Our heroines are pure, kind and believe in the power of friendship. There's lots of banter with their school friends. No one recognises anyone else in their civilian clothes, even though they've all seen each other's faces and no one wears masks.
Basically, it's old-school. There's not much difference between this and PreCure, except the episode count and budget. (This is a cheaper show.)
That said, though, I liked it quite a lot. It's going quite far with its character work and it's pushing its heroines. The enemy-ally line can be fuzzy. People can be redeemed, maybe, but then you remember that fights in this show are theoretically to the death. (The baddie in ep.1 looked pretty dead afterwards, while the girls mow down an awful lot of evil henchmen with those huge bladed weapons. Admittedly their victims glow and vanish instead of exploding with gore, but you don't expect any of them to get resurrected afterwards either.)
Meguru and Sumire are in the last year of middle school. Meguru is a bubbly, optimistic friend-of-everyone who's just moved to Tokyo from the middle of nowhere. She'd love to be a Twin Angel, i.e. a magical girl. Sumire is an unfriendly, withdrawn girl with no social skills who just wants to stop being a Twin Angel and for preference stop interacting with any other human beings except her brother. (She likes him a lot. How much? Too much. "As long as I have my big brother, I don't need anyone else.")
I enjoyed this series, but it doesn't feel very unified. It has three phases, I think:
SECTION 1: GENERIC MAGICAL GIRL SHOW
The villains aren't very important and it's all about our main duo. (Oh, and the hedgehog. Their mentor is a talking hedgehog.) At first it's hard work just getting Sumire to talk to Meguru, let alone go on patrol with her. Her, uh, brother-worship is being played to the hilt, while the show isn't afraid to be silly. Ep.2 has animals in a pet show all running in a race, but one of them's a snake. (That's implausible enough even for much more social animals, e.g. cats.) Why does the snake join in? Why doesn't it just ignore everyone and slither off? In fact, why isn't it just eating its fellow contestants?
Our heroines' classmates are similarly cartoonish. There's a girl with a sheep hat who says "baaa", a cross-dressing boy, an occult maniac and a girl whose only character trait is having slightly larger boobs than the others. Oh, and I don't see what's so evil about the baddies turning people's life energy into medals. Their victims just go and relax in an onsen afterwards or something.
That said, though, Billy Tanaka is quite funny in ep.4. Over the top and delusional, yes, but a laugh when he finds love. This phase of the show is mostly just genre filler, with the main story being the developing Sumire-Meguru relationship. (Sumire can be hard work.) I enjoyed it, though. The cast are likeable and the episodes are fun.
SECTION 2: THE RUSSIAN TWINS
(This show's villains sometimes have unstated nationalities. Mary's American because she's blonde, buxom and peppers her dialogue with gratuitous English.)
Anyway, new villains take the stage... and Meguru befriends one of them. They're cluess about the world. Meguru often has to explain perfectly normal Japanese to them. This is a simple storyline that's been done before in other magical girl shows, but I found it surprisingly well done. It's sincere, it made me care and it's capable of springing logical surprises.
This also has the unexpected side effect of pulling Meguru away from Sumire, which until now had seemed to be the show's heart. When Sumire fails to say the obvious, necessary thing at the end of ep.8, you could either see this as idiot plotting or as characterisation in the light of this. (To be honest, I see a fair amount of the former.)
SECTION 3: THE FINALE
There's a lot in these last three episodes. Meguru falls apart emotionally. Zelucifer disappoints. (Seriously, after all that build-up?) There's a huge callback to the show's parent series, which was surprisingly effective even though I'd never seen that.
I enjoyed this show a good deal. It's wallowing in genre cliches and almost proud to be dumb sometimes, but it's sincere and it works if you're prepared to forgive a few cartoonish bits. I also liked the musical animals in the end credits. There are much stronger magical girl shows out there and I'm sure genre afficionados would put it only halfway at best, but for me this one worked.