
It is a taboo story about love and incest between twins. It's not about sex, it's about the feelings the two have for one another and how society views them.
Boku wa Imouto ni Koi wo Suru is a Japanese movie of 5,382 characters, with 616 unique words and 279 different kanji. Its difficulty rating on Jiten is beginner, 0.9 out of 5. The full vocabulary list ranks all 616 words by how often they appear, and you can study them on Jiten or download them as an Anki deck.
This title is too short to reliably find similar media.
Here are some of the words that appear most often in this media, as well as a sample of its rarer vocabulary.