Bijin no Ane ga Iyagatta node, Dou Mitemo Sugatae ga Shirobuta no Jiki Hakushaku ni Totsugimashita Tokoro

The man her sister forced upon her was the perfect husband, even cuter and more handsome on the inside than he looks! "I really wanted to go, you know? But no matter how you look at it, we're not a good match. So you go, I'm sure you'd suit each other." Mimosa, the second daughter of Viscount Norton, is to marry the obese next Earl, whose portrait looks deceiving no matter how you look at it, in place of her beautiful sister. Unlike her glamorous and sociable sister, Mimosa is a shy, reclusive 17-year-old who is not only shy but also reclusive. Since the Earl's family preferred her sister, you'd think she'd be turned away immediately, but...huh?! She's actually welcomed with open arms!? A love story between a timid young lady and a pure-hearted knight, beginning with their newlywed life! (Source: Square Enix, translated) Note: Includes ten extra chapters.