Warning! Spoilers ahead for Diamond in the Rough chapter 2!
Mangaka Nao Sasaki essentially retells Fullmetal Alchemist as a revenge story in his ongoing series Diamond in the Rough by replacing the Elric brothers' search for the philosopher's stone with this new manga's version of Alchemists, known as ore craftsmen.
Other similarities abound, even a tragedy that transpires before the events of the manga. But rather than the brothers Edward "Ed" and Alphonse Elric trying to correct the natural death of their mother with alchemy and getting deformed in the process, Diamond in the Rough flips this dynamic. Kai's familial tragedy occurs not in response to but because of his world's version of alchemy - whereby an ore craftsman draws out the inherent abilities of stones or channels the power of gemstones through themselves. In his case, Kai's family is petrified in stone. And it is through this tragedy that Kai becomes "blessed" with the abilities of an ore craftsman through his own deformity, no less.
The brothers of Fullmetal Alchemist have no one to blame but themselves unlike Kai, so they delve into books, studying the power of alchemy to restore themselves and to possibly bring their mother back from the dead. Their studies eventually lead them to the mysterious Philosopher's Stone, which the boys quickly embark in search of. Their quest, unfortunately, isn't that straightforward, taking many detours as other forces come between them and the Stone, most especially the Homunculi and their leader Father who desires to use the Stone for his own nefarious means. Conversely, Diamond in the Rough's Kai has a very different target. He knows that the man who attacked his family is an ore craftsman with a particular earring. But he doesn't have a brother to help him like Ed and Alphonse had in each other. Luckily, Kai becomes the apprentice of a traveling ore craftsman named Akaboshi who just so happened to be passing through Kai's village at the time.
In essence, Akaboshi takes on the role of Ed since they are both professionals in their respective fields while Kai is more closely comparable with the less experienced and young brother Alphonse, for Kai is only 15 while Akaboshi is an adult. The key difference, however, is Alphonse initially has no power unlike Kai. In this way, Diamond in the Rough is superior to Fullmetal Alchemist, as the power-wielding Kai knows nothing about his abilities and therefore has much more to learn than Ed who's already an incredibly gifted Alchemist by the start of the manga. In stark contrast to Ed, the possibilities for Kai are boundless at the start of his journey, creating a stronger feeling of wonder for his character.
In the same vein, Diamond in the Rough is not only driven more so by revenge but hope. The Elric brothers have really nothing else except the Philosopher's Stone to bring their mother back from the dead. But even then, their situation is hopeless, for as readers are told at the beginning of Fullmetal Alchemist, "To obtain something of equal value must be lost." And the manga makes it abundantly clear that human life is priceless, so how can you put a value on something that has no price? Meanwhile, Kai's hope lies in the ore craftsman who petrified his family, and it's very likely that the perpetrator possesses the cure to their petrification. But one question remains. Will Diamond in the Rough's world have an equivalent to Fullmetal Alchemist's Homunculi? Diamond in the Rough is available on the Manga Plus app through Jump Plus.