Kazuya Souma talks with his grandfather about why people form families. Having already lost his parents and grandmother, his grandfather is the last family he has. The opening ends with Kazuya musing on his grandfather's words. Suddenly, he's greeted by a king declaring him to be a hero. Disoriented by what's going on, Kazuya starts asking questions about the situation he suddenly finds himself in.
Kazuya was summoned into the Elfrieden Kingdom on the continent of Landia. It's a mostly fantasy medieval world, with the recent rise of monsters and demons appearing on the opposite side of the continent from Elfrieden. Since they're not fighting directly, Elfrieden was offered the choice between paying war subsidies or summoning a hero and handing him over to the Gran Chaos Empire. Upon finding this out, Kazuya spends days with King Albert and the Prime Minister, trying to find out how to avoid being handed over. After two days of conversations, it's been decided: Albert is abdicating the throne and Souma Kazuya will take his place, as well as marrying Princess Liscia to legitimize his taking the throne, an outcome that Kazuya didn't see coming.
With that decided, Kazuya turns to trying to turn things around in the kingdom, which is facing a number of problems: a food crisis, corrupt nobles, and possible invasion from the next door Principality of Amidonia, to name the most urgent. Souma rushes through some reforms based on knowledge from his world, but realizes he's going to need much more, putting out a call for anyone with great talents that he can put to use.
Broadcast to the entire kingdom, Souma gains five great allies:
- Aisha Udgard, a dark elf who is the greatest fighter in the kingdom.
- Juna Doma, judged the most beautiful and greatest singer in the kingdom.
- Hakuya Kwonmin, who is constantly reading and has a prodigious memory.
- Poncho Pannacotta, a nobleman who spent his fortune traveling the world to try different foods.
- Tomoe Inui, a mystic wolf girl who can speak to animals.
Souma hires all of them to various roles supporting him, and sets out using their skills to help solve the various problems in the kingdom. They make great progress towards solving the food crisis, but the outside conflict with Amidonia is anything but settled. At the same time, the three Dukes, powerful military figures meant to keep the king of Elfrieden from getting too powerful, have their doubts about Souma's leadership.
Tropes:
- Abdicate the Throne: Albert does this within days of meeting Souma.
- Altar Diplomacy: Albert arranges for Souma to marry Liscia to give him more legitimacy to the throne.
- Armor-Piercing Question: Souma asking Hal what he thinks is going to happen to his childhood friend Kaede, one of the king's troops, if the rebellion is successful.
- Arranged Marriage: Albert announces one between Souma and his daughter, Princess Liscia, to legitimize Souma taking the throne.
- Balance of Power: There's a strange one in the Kingdom of Elfrieden, where the king is human but there are many other non-human races. There are three Dukes of different races in charge of the military, intended to take out the king if they believe he is using his power against the other races. Throughout this volume, the dukes are starting to move against Souma, led by Georg Carmine, commander of the army.
- Big Eater
- Poncho is mocked for this, but Souma recognizes his knowledge of unusual food is exactly what the kingdom needs to get through the food crisis.
- Aisha is this once she starts spending more time outside the God-Protected Forest.
- Bullying a Dragon: Hal threatens Souma right in front of him, leading to Liscia, Aisha, and Juna all pulling weapons on him at once.
- Character Focus: Shifts a lot, usually without indicating who the current viewpoint character is. Used for dramatic purposes when telling the recruitment scene from Hakuya's perspective.
- Death by Origin Story: Souma's parents and grandparents, all dead by the end of the prologue.
- Easy Logistics: Averted - the food crisis in the kingdom is largely a result of just how difficult logistics are in this world, and one of Souma's main projects is making a transportation system to make logistics much easier.
- Elemental Powers: Magic in this world is divided into air, fire, water, earth, light, and dark.
- Establishing Character Moment: Several, as much for the other characters in the story as for the reader:
- Liscia thinks that Souma is a usurper, forcing Albert's abdication and their marriage. When Liscia finds Souma, he's exhausted from days of working with almost no sleep and immediately conscripts her into helping with paperwork, without even bothering to find out who she is, only if she can read, write, and do math.
- Aisha comes off at first as reserved and distrusting of people outside of the God-Protected Forest. When Souma unintentionally predicts all the problems in the forest and talks about methods to prevent them, Aisha immediately switches to proclaiming her loyalty to him, no matter what he asks of her.
- Hakuya forces this on Souma to evaluate how good of a ruler Souma would be. He knows that, while Poncho doesn't at first look like someone to be taken seriously, his knowledge of food is essential to solving the food crisis. When Souma declares that Poncho is exactly the kind of person the kingdom needs, Hakuya changes to approving of Souma and offers his skills in service of the kingdom.
- Everyone's Baby Sister: Tomoe is this by the end of the volume.
- Fantastic Racism: Notably averted by Elfrieden, not so much for many other nations in the world.
- Gender Is No Object: This is already largely the case in the kingdom, as many women hold important positions with little comment. Souma doubles down on this, trying to find the most talented people no matter what.
- Giving Radio to the Romans: Most of Souma's policies and reforms this early on. Creating educational shows with the Jewel Voice Broadcasts, vastly improving hygiene, and introducing periodic thinning to the God-Protected Forest are just a few anachronistically advanced ideas he brings to the otherwise mostly medieval technology in Elfrieden.
- Heart Is an Awesome Power: Souma makes an impression by deliberately seeking out people with overlooked talents.
- Poncho is mocked for being an overweight noble who spent all his money on food. Souma recognized this as being crucial to getting past the food crisis, as the foreign foods Poncho was familiar with were usually overlooked or thrown away in the kingdom, giving them a way to increase their food supply.
- Hakuya was a recluse who spent all of his time reading. Souma slowly realizes Hakuya's encyclopedic knowledge and cunning makes him the perfect candidate for prime minister.
- Tomoe is a refugee girl that citizens of Elfrieden looked down on. Her ability to talk to animals makes her essential for things like the Kingdom's transportation network.
- Interservice Rivalry: Done deliberately in the Kingdom of Elfrieden. The king is human, but there are many other sentient races in the kingdom. To keep the king from persecuting the other races, he has a small number of troops, but the Navy, Air Force, and majority of the Army are under the control of the three Dukes, who come from other races.
- King Incognito: Souma goes out into the city in disguise, trying to have a date with Liscia while showing her what he's trying to do to improve the kingdom.
- Land, Sea, Sky: The Army, Navy, and Air Force, each controlled by a different duke.
- Medieval European Fantasy: The Kingdom of Elfrieden
- Mundane Utility: Souma uses his magic to let him sign multiple papers at the same time.
- Name Order Confusion: From constantly introducing himself as "Souma Kazuya", everyone in Elfrieden, which uses the Western order, assumes that "Souma" is his given name. By the time he realizes this confusion on his date with Liscia, it's too late to change, so Souma he is for the rest of the story.
- Nice Guy: King Albert. He became the king and stayed in power by being so inoffensive that he never made any enemies - but it also made him a completely mediocre king.
- Not Distracted by the Sexy: When Liscia first meets Souma. Under other circumstances, he might be distracted by her beauty, but he's been working so much that all he cares about is if she can help him look through budgets.
- An Odd Place to Sleep: Souma sleeps in his office because it'd take too long to get up and walk into the office each day.
- One-Man Industrial Revolution: Souma tries to do this, bringing 21st century knowledge into a medieval kingdom. His success is limited by being a history student, not an engineer, and having to learn how magic changes a lot of his assumptions.
- Paper-Thin Disguise: When Souma wants to go around the city unrecognized, he puts on a straw hat and a cape.
- Pragmatic Hero: Souma sells a lot of the kingdom's treasures, eats in the cafeteria with soldiers, and hires people based on merit, not their positions.
- Raised by Grandparents: Souma, while he was back on Earth.
- Royals Who Actually Do Something
- Souma, from even before he actually is named as king. This is one of his defining traits, pushing through new policies and constantly dealing with the paperwork in being a ruler.
- Liscia, far from being a spoiled princess, has been trained as a military officer, along with helping Souma with all of the paperwork he has to do as king.
- Schizo Tech: Due to having magic, while Elfrieden looks mostly like medieval Europe, some surprisingly advanced things exist. From using wyverns to develop a medieval air force to technology no one understands found in dungeons, like the jewel for doing Jewel Voice Broadcasts.
- Secret Test of Character: Hakuya tests Souma on how well he appraises Poncho. Also serves as an Establishing Character Moment for how perceptive and cunning Hakuya can be.
- Speaks Fluent Animal: Tomoe can speak to animals. While useful on its own, this takes on a whole different level of importance when she reveals that this means she can also speak to demons. No one even considered that demons might be sentient before.
- Translator Microbes: Souma has no difficulty with verbal or written communication with anyone thanks to the magic that summoned him to this world.
- Trapped in Another World: The basic premise of the story.
- War Refugees: One of the big problems facing the Kingdom, as so many people were displaced by the expansion of the Demon Lord's Domain. How quickly and enthusiastically Souma brings in Tomoe, one of the refugees, helps set the tone for how he'll run Elfrieden as their king.
