Manga adaptation Volume 2 out on July 12th!

Final Volume! Fully original story Volume 3 out on November 10th♡

Extra stories are being updated irregularly, so I've listed it as ongoing.

Lady Iris Karelia, daughter of a Marquess, had her fiancé stolen by her younger sister. What's more, she was forced to marry Baron Lucas Stock, a nouveau riche merchant and former commoner who had taken over her family's debts.

"I'm a nouveau riche who gained my peerage through money. I know nothing about high society's information or its unwritten rules of etiquette. I want you to teach me everything you know about the capital."

"If someone as plain and unremarkable as I am can be of help, I will gladly lend you my strength, Lord Lucas."

Iris, supporting her husband Lucas with the knowledge and refinement of a former noble lady, gradually finds happiness. Meanwhile, her younger sister and family, whom she left behind in the capital, lose the support of Iris, whom they had scorned as "plain and unremarkable," and begin to rapidly decline...

2021/06/01:

Highest Ranking: Daily Overall Ranking #1 / Isekai Romance Ranking #1 / Weekly Overall Ranking #2 / Weekly Isekai Romance Ranking #1 / Monthly Isekai Romance Ranking #3

※Also available on Everystar, pixiv, and Kakuyomu.

(Old Title: The "Unremarkable" Older Sister Whose Engagement Was Broken Now Marries a Former Commoner, a Nouveau Riche from the Provinces, in Place of Her Younger Sister. He's a Bit Rough Around the Edges, but I Think He's a Wonderful Person.)