Eliana, the daughter of the Duke of Lumiere, has been working hard for years to be the best marriage candidate for the Crown Prince of Grenvale in the hopes of pleasing her father and bringing prestige and honor to the Lumiere family.Her efforts finally pay off and she ends up getting engaged to the prince despite not having any feelings for him. Things go awry however, when Eliana's bratty little sister, Luna, demands that her hand in marriage should be given to the prince instead as she is the one who truly loves him. Luna ends up throwing a fit and refuses to get out of bed for days until she is given what she wants. The Duke of Lumiere gives in, believing that it doesnt really matter which of his daughters marries the prince as their social status isnt going to fall any further.
When Eliana hears that her engagement to the prince will be given to Luna instead, she runs into her room in despair. She then looks up and a painting of a dragon and decides that in order to give her family she will sacrifice herself as a dragon bride to give her family prosperity. But just when she jump off a cliff into pool of magma, a huge red dragon swoops in and swallows her. He quickly spits her once he realizes she is a human.
After Eliana comes to, she's to see that there really was a dragon at the bottom of the crater. The dragon then shifts into his human form and introduces himself as the "Avaricious Greed" of the seven dragon pillers and decides to humor the dragon bride custom of her culture by taking her in as his "bride".
Imouto ni Fianse wo Yuzure to Iwaremashita, Saikyou no Ryuu ni Kiniirarete Masakano Okoku Nottori?(妹に婚約者を譲れと言われました 最強の竜に気に入られてまさかの王国乗っ取り) note is a web Light Novel and manga series written by Kashiwaten with illustrations by COMTA and hi8mugi.
- Barbie Doll Anatomy: When nudity occurs in the manga, certain attributes are notably missing.
- Finger-Suck Healing: Greed sucks on Eliana's finger in order to remove a splinter, much to her embarrassment.
- Girlish Pigtails: Luna has her hair done in two pigtails. It's fitting condsidering how childish and irresponsible she is.
- Hyperspace Wardrobe: Jill magically dresses herself with her vines after Eliana asks her to wear clothes.
- Long Title: The series has an extremely long title even by light novel standards.
- The Needless:The horse familiars Greed creates with his magic do not need to eat or sleep and can't reproduce.
- You Gotta Have Blue Hair: Luna has pink hair, The Sovereign of the Dryads/Jill has green hair and Eliana has silver hair.