If you've ever wondered what exactly Konosuba is making fun of rather than mere genre specifics, take a peek at Patora Fuyuhara 's In Another World With My Smartphone . That's not to say that this series is precisely the basis for Natsume Akatsuki 's parody, but it is certainly closer to the base plot of Fuyuhara's story, wherein an ordinary young man dies unexpectedly and is offered the chance to be reincarnated in a parallel fantasy world. While Fuyuhara's series isn't strictly serious, it still hits a lot of the points that Konosuba makes fun of.

The base story of the first novel is that sixteen-year-old Touya Mochizuki decides to take a shortcut home on a rainy day and is struck by a bolt of lightning thrown by God. God, feeling badly about the whole thing, because Touya was supposed to have had a long life ahead of him, offers him the opportunity to be reborn in a parallel world. To sweeten the deal, Touya will be his same age, have all of his knowledge, and can take one thing with him. Oh, and as a further measure of God's distress, he'll also have his physical and magical status boosted, to give him a head start. Touya, who feels kind of badly for the grandfatherly figure, agrees, and asks to take his smartphone with him. God's only stipulation there is that he can't call home to the “real” world; otherwise all functions will be as they were.

To say that this is a pretty damn good offer is perhaps an understatement. Not only does Touya land in a Medieval world, he's got instant maps and dictionaries at his fingertips, a camera, and enough contemporary cultural knowledge to make him popular, especially when he teaches the locals about ice cream. God then went above and beyond by giving Touya ridiculous magic abilities – in this world, magic is divided into seven classes, and while most people can only use between one and three, Touya can use all of them, including the impressive Null magic. Overpowered nature aside, this magic is one of the more interesting world-building components of the story. While the other types of magic are the usual elemental categories (earth, air, water, fire) or alignments (light and dark), Null magic is described as personalized, the kind of magic that can do basically anything based specifically on the person who uses it. No two people have the exact same Null magic, and each spell is essentially born with its wielder. While some Null users can learn others' spells, that's by no means a guarantee.

Of course, for Touya it pretty much is a certainty, and the driving force behind his success in the new world. To Fuyuhara's credit, the magic is pretty much all he has going for him, apart from access to maps – he quickly discovers that although the world functions basically like his previous one, it's still different enough to be confusing, and God has not seen fit to grant him abilities like literacy or a basic understanding of the political or financial system. Fortunately for Touya, he quickly meets up with twin sisters Linze and Elze, who take him under their wing as a party member, helping him to sign up as an adventurer with the guild (saved from bog-standard LNness by the fact that there are no status windows, levels, or anything else gamelike) and eventually teaching him to read and write. Although the book does eventually venture down harem lane, Touya's first three female encounters are devoid of romantic feelings, and he and the twins form a solid friendship.

It isn't until the latter half of the novel that things start to go south, or at least take a turn for the more familiar. After saving the life of the king and helping to catch the culprit in a shout-out to Detective Conan , Touya finds himself faced with an over-amorous twelve-year-old princess bent on marrying him. Apparently twelve is a perfectly acceptable marrying age in this world, and given Touya's powers, the royal parents are thrilled to bring him into the family. While to a degree all of this makes sense, it also marks the start of a slide into much more standard light novel territory, with the other girls in Touya's party suddenly developing feelings for him pretty much overnight. It's also handled very unevenly – Fuyuhara goes from having everyone acting like they did previous to the princess' introduction to abruptly shifting to scenes of jealousy or statements about how polygamy is accepted and the girls would be fine with it.

On the whole, that's the major issue with this novel – Fuyuhara doesn't seem entirely certain what they want to do with it. Is it an isekai adventure? A harem story? Why send Touya with his phone only to barely utilize it? There's also one bizarre and somewhat troubling moment when Elze and her sister have “girl problems,” which are implied to be cramps so bad that they can't go out. While it's kind of nice to see something so normal (but not talked about) featured in the book, Fuyuhara goes on to say that healing magic doesn't work on menstrual cramps because it's not an illness, but rather a sign that your body is functioning properly. This is a problematic attitude to say the least, and if it isn't precisely used to imply that the girls are somehow weak, it certainly doesn't indicate a proper understanding of reproductive health that it is troubling to see.