Oniichan Control. Third-year-old Goushi Hirose loves his little sister Noa a little too much, even keeping pictures of her and her pillows. He's going to Tokyo to get away, hoping to suppress his feelings for her sake. He lives alone, every single day as he fantasizes about his sister.
His girlfriend calls him, three years later. He informs him he will take an entrance test at Myouzen University, a school near his. Noa passes her entrance exams and marks the beginning of the life of the siblings together in the one-room apartment. Goushi knows nothing, Noa loves him too, just in a more absurd way than himself! She will do whatever she can to make her brother loyal to her while she tries to hold rivals at bay and threats to their affection.