
The one who fulfills my desires is the younger sister of the person I love―. A love triangle between the perfect older sister and her care-free younger sister. I, Yuka Amamiya, confessed my feelings to my first love, Nagisa Hanabusa... but I was rejected. Unable to let go of my lingering feelings, Nagisa's younger sister and my friend, Mino-chan, made a surprising offer. "I'll help you forget all about my sister." She offered to let me do everything I had wanted to do with Nagisa — but do it to her instead. I saw the shadow of the person I loved in her younger sister, and I started going on dates with Mino-chan, dressed as Nagisa, and... "Yuka-senpai, you're about to kiss a dear friend who's like a little sister, right?" I indulged in my desires, almost drowning in them. As I spent more time with Mino-chan, who was supposed to be a substitute for Nagisa, I found myself gradually falling for her― (Source: Kadokawa, translated)
Suki na Ko no Imouto is a Japanese novel of 317,267 characters, with 7,033 unique words and 1,539 different kanji. Its difficulty rating on Jiten is easy, 1.8 out of 5. The full vocabulary list ranks all 7,033 words by how often they appear, and you can study them on Jiten or download them as an Anki deck.
Here are some of the words that appear most often in this media, as well as a sample of its rarer vocabulary.