Do S na Oniichan to no Atarashii Koi no Hajimekata Oshiete KudasaiドSなお義兄ちゃんとの新しい恋のはじめ方教えてくださいっ！ ; 家の中のSな事 ; 1 新しい家族と一つ屋根の下 ; Ie no Naka no S na Koto ; Sadist in the House

Shiori's dad remarries and she couldn't be happier. Not only has she gained a new mom, but a hot, older, yet sadistic brother as well?! Note: The manga was previously named as Ie no Naka no S na Koto.