Onii-chan saimin, also known as お兄ちゃん催眠, is a compelling Japanese web novel that delves into adult themes of romance and slice of life. The story follows a male protagonist who, upon regaining consciousness, finds himself repeatedly violating his sister. With tags such as brother complex, hypnotism, and incest, this novel explores complex relationships and taboo subjects, making it a captivating read for those interested in mature storytelling.