In a peculiar twist, my charming sister Akari's overwhelming love for me takes a dark turn. Unbeknownst to me, she meticulously documents my every move in the 'Onii-chan Notes,' revealing a side of her I never knew. As I stumble upon surveillance equipment in my room, I uncover her unsettling plan to keep me by her side forever. Determined to set boundaries and protect our relationship, I must navigate this intricate web of affection before it consumes us both.