The Dragon's Soulmate is a Mushroom Princess!

Love At First Mushroom
As a result of the divine spirits’ protection, Agnes has an unusual and often embarrassing power: whenever she experiences strong emotions, she makes mushrooms sprout on people! One day, her royal fiancé, who claims to have dragon’s blood, breaks off his engagement to Agnes claiming to have found his true soulmate. Her reputation tarnished, Agnes vows to return to commoner life, when she’s unexpectedly summoned to a ball by her ex-fiancé’s cousin, a prince who is far from horrified by her mushrooming him.
“This is fate! I promise you, it’s no spore-of-the-moment decision! My morels are not questionable! You and I would make the mushiest couple imaginable! Would you marry me?”
Agnes has a lot to deal with: her personal “flaws”, an endless onslaught of mushrooms, and the attentions of a prince with a serious fungal fetish. Can Agnes get through this and face up to her true self, or will it all prove just a little too mush?

[From Cross Infinite World]