Manga by author Rokushou Kokuu

Love comedy starts at a company drawn by the ROKUSYO Kokuu of "Im an older brother but love isnt relevant", "Editor of different world publication"! "Some girls from the same department are approaching me for some reason! But there is a reason why she can't get out of hand

***A young "older" sister suddenly appears before me...?! A love-comedy of "irregular" siblings living together. ***Asami, a beautiful but mysterious girl appears before Ryosuke, the protagonist who is in his thirties, and claims that she is his sister. She is the sister of Ryosuke's brother's wife, in other words, she is somewhat Ryosuke's sister... Aiming to be the ideal older sister, she decides to engage in extreme big sisterly acts!