A Japanese salaryman falls asleep before waking up and finding himself as a five year old boy named Wendelin von Benno Baumeister, during the wedding of his oldest brother Kurt and his wife Amalie. Despite being nobles, Wendelin discovers the Baumeisters are poor and only owns small farmlands which most of it will be inherit by Kurt while the rest of his six older brothers have either married into another family, finding work as a government official or soldier, leaving him nothing to inherit. Wendelin later discovers he has the ability to use magic

Wendelin decides to keep his magic a secret after learning it moves him ahead of Kurt in the line of family inheritance, risking assassination attempts from Kurt. Alfred discovers Wendelin has an extraordinarily high magic capacity. Alfred displays several unusual symptoms, cold skin, no sense of taste and bouts of physical pain

At Adventurers Academy Wendelin tries to make friends but due to his lack of communications skills and high level of magic, the rest of the students are too afraid to approach him. Three students, Erwin, Louise and Iina, share a bond over being the youngest children of lower class families. Wanting to gain Wendelin's recognition, they attempt to hunt a large pack of wolves but are overwhelmed until Wendelin rescues them

Wendelin and his friends are invited to his brother Erich’s wedding. An undead dragon attacks their airship so Brantack has Wendelin purge the dragon with holy magic before collecting the valuable bones and crystal heart. In the capital city, Stuttburg, Brantack leaves them with his friend Aruterio Marchen

Hohenheim introduces Wendelin to Elize then, due to his naiveté, tricks Wendelin into forming a political marriage with Elize. Wendelin panics at the idea of marrying a woman he doesn’t love, but is later assured by Erich that nobles rarely meet their betrothed until the wedding. As he is swarmed by unemployed adventurers every time he leaves his home he hires a grateful Erwin as his retainer

Elize visits Louise, Lina and Erwin to learn exactly what sort of man Wendelin is. The King asks Wendelin and Brantack to slay an ancient dragon, Greigorland, as the kingdom needs his territory for farmland. He also sends Klimt Kristoff von Armstrong, his enthusiastic and brawny court wizard

At the wedding of his brother, Helmut, Wendelin learns he is expected to participate in a martial arts tournament, but as a noble he must use a sword instead of magic. Louise and Lina decide to participate as well. Erwin is convinced to participate by Brantack

Three years later Kurt, Wendelin’s eldest brother, receives a letter from Head Auditor Ruckner, Lord Commissioner Ruckners brother, that Wendelin has died. Five days previously Wendelin finally turns 15 and registers their adventurer party as the Dragon Busters, so the King sends them to investigate ancient ruins. Brantack explains the ruins were discovered in Greigorland’s territory and many high ranking adventurers have disappeared

For the ruins' treasures the King pays Wendelin’s party ten million gold. Wendelin decides to move their home to Breichburg to set up their adventuring careers. Armstrong reveals the rumours about Wendelin’s death, causing Wendelin to realise their success has attracted enemies

Brantack explains to Wendelin’s father, Sir Artur, that the deceased expedition army, which Alfred Rainford was part of, are now zombies. As the zombies are on their land, Artur is entitled to 30% of any profit gained from the zombies' materials. Kurt greedily demands 50% and tries to insist the zombies and their belongings be left in the forest instead of being given proper funerals

Brantack explains the King wants to develop the surrounding land but is unable due to the current land owning lords, like Sir Artur. Instead, the royal court has been secretly driving Kurt mad with jealousy over Wendelin, so that when he snaps he will be removed as heir. Wendelin refuses to participate as it would also mean disinheriting his nephews

With the magical Dragon's Flute that will summon a horde of dragons, Kurt lures Wendelin and company to an empty clearing in a forest. Kurt, after mocking Wendelin and Bramtack's failed attempt to stop kurt, plays the flute to kill the party and punish the towns for betraying him. It quickly becomes apparent to the companions the flute is not summoning a horde of dragons, but instead channeling all the malice of the land into Kurt