It's charming, happy and kinky. Everything that happens is consensual (although you'd have been worried had this been real) and everyone who has sex made the decision freely and enjoys it. Also, everyone who matters is likeable and I'm happy for our romantic couple.

Our hero Takuya works in a convenience store and is a fan of a cosplay idol called Nazuna Suzushiro. What makes him happiest in ep.1 is meeting her for a few seconds at a handshake event and buying her DVD. As he's going home, though, he bumps into a mildly sinister but polite old gentleman who can teleport while you're not looking. This gentleman is also carrying what looks like a DVD case. These similar-looking objects both fall on the pavement. Guess what happens.

Incidentally, one's natural assumption is that the mix-up was an accident... but I'm not sure. I wouldn't be surprised if that gentleman had been conducting a deliberate experiment.

Anyway, Takuya's lost his DVD and gained a foetus that can grow in a few seconds into an adult woman. Her name's Seri and she can shapeshift into any form you request, complete with DNA analysis of the target (when available) and the ability to adopt the target's voice and personality as well. She even has an instruction booklet. "This sexanoid Seri will change her cell arrangement and service you in any form. Please be aware it will start growing in about five minutes after opening. After a week..."

Seri's great. She's funny, goofy and enthusiastic about fulfilling her programming. Her shape-changing has a sense of humour and she enjoys sex. She's also the main driver in the relationship. She's always gung-ho about everything, but she freaks out Takuya when she turns into Nazuna. "I can't! I can't defile Nazuna! She'd never do anything dirty! She never even needs the toilet."

The story has an A-plot and a B-plot. One is just Takuya and Seri playing around with shape-changing possibilities, which gets mildly worrying when Seri play-acts as his colleagues at the convenience store. (I don't think this breaks any law and it's just private role-play between two people, but I'm sure the colleagues in question would be creeped out if they knew about it.) Seri's even capable of turning into anime characters (once in 2D) and weird size-changing. This isn't paedo-pandering. Once, it's like making out with a Titan (and in one shot I half-expected her to eat him). Then, next time, Seri becomes 30 cm tall, but with normal adult proportions. No real-world fetish corresponds to that. Takuya's invented a brand-new kink.

Seri's other transformations include Urusei Yatsura's Lum, Lupin III's Fujiko Mine, Nagai Go's Cutie Honey and Leiji Matsumoto's default willowy blonde (although I think this one might be Maetel from Galaxy Express 999).

The B-plot involves Takuya's co-worker, Suzuna. She's rude to Takuya, but I liked her and their conversations are amusing. She's not telling the truth and she might have a stalker problem. I enjoyed this storyline and it does an good job of carrying the two-parter, making it a proper narrative with stakes and consequences.

The ending's a bit of a shock, but it could have been much darker. Seri's not dead. I'd like to think she'll end up somewhere else and have fun there too. The humans' stories have a romantic ending, despite the threesome scene where Seri tries growing a penis. In short, it's lovely. In its freaky hentai way.