The Secret Etiquette of Lady Takashima. is a Manga/Manhwa/Manhua in english language, SUGGESTIVE series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

To Lady Takashima, the breach of etiquette is deserving of the death sentence. As the hate towards the lack of manners arises within her, the feeling of "I want to try it" has also arisen within her. This work is the record of the daily life of the Ojou-sama struggling with her guilt.