My Younger Stepsister with whom I have never spoken to is an online friend from a game into which I have been fooling around for years. (Associated Names)

Kurai Subaru of high school 2nd grade who loves games. His father remarried 5 years ago, and he lives with his younger stepsister, Hiyori, who attends the same high school as his. Although he was not dissatisfied with his life, there was a wall between him and his quiet younger stepsister Hiyori, which he was…