Elm, the immortal and world-weary strongest Dragon Knight, has spent centuries serving the corrupt Namu Kingdom. Despite repeatedly saving the world, he was exploited by hundreds of SSS-rank nobles who bought their titles and outsourced all difficult quests to him, paying him next to nothing. Exhausted and disillusioned by humanity's endless conflicts, Elm, encouraged by his loyal companion, Bahamut XIII (the strongest evil dragon in the form of a cute baby dragon), decides to abandon his post and seek a peaceful, anonymous life in the countryside.
Elm swims to the Nogard Continent using his legendary "Willm Mail" armor. There, he saves Uliko Boguya, an energetic and naive 15-year-old village girl, from an SSS-rank monster. Uliko, possessing powerful appraisal eyes, mistakenly believes Elm's legendary gear is high-quality cosplay, a misunderstanding Elm finds convenient for his goal of blending in. Uliko guides him to her struggling Boris Village, which is plagued by a resurfaced Stone Sickness. Elm secretly crafts a potent elixir using his "Craft Mode" armor, curing the villagers and accidentally rejuvenating them. His act of kindness, witnessed by Uliko, reveals his true power, but she agrees to keep his secret. One of the cured villagers, Shogun, a respected former warrior, becomes Elm's staunch supporter, helping him gain acceptance in the initially wary village.
Elm purchases land with his vast hidden wealth and, using perception-blocking magic and his "Craft Mode," quickly constructs a sturdy house from dragon-bone reinforced bricks, much to Bahamut's amused commentary and the villagers' later astonishment. Meanwhile, Elm's departure from the Namu Kingdom plunges it into chaos, as the hundreds of SSS-rank quests he was secretly handling go unfulfilled, leading to widespread disaster and revealing the kingdom's reliance on him.
Back in Boris Village, Uliko, now harboring a crush on Elm, informs him about a newly discovered dungeon filled with S-rank monsters, a source of despair for the village. Motivated by his innate kindness, Elm clears the first floor using his "Magic Mode" to instantly incinerate all monsters, leaving behind valuable S-rank loot. He gifts this treasure to Uliko's struggling armor shop. A merchant, drawn by rumors, buys all the valuable gear, revitalizing the shop and bringing hope to the village. Elm advises Uliko to expand her shop and build an inn to prepare for the influx of adventurers.
The merchant's reports reach a revered Hero, who arrives in Boris Village. Elm guides the Hero to the dungeon, observing her fight an S-rank boss. When the Hero is injured, Elm instantly heals her with a simple spell. The Hero's helmet falls off, revealing she is a woman. Elm's non-judgmental acceptance deeply touches her, sparking romantic feelings. Elm asks the Hero to develop a dungeon strategy guide, intending to spread it for free to help the village, further impressing her with his selfless nature.
Elm's journey begins with a desire for a quiet life, but his immense power and inherent kindness continually draw him into helping others, inadvertently making him the catalyst for Boris Village's revival and attracting attention from powerful figures, hinting that his peaceful retirement may be anything but simple.
