This is one of the better setups to have the main heroine fall in love with the MC that I've seen from these types of manga.
Plot seems pretty straightforward but the art is nice and the characters seem solid so I'll give this one a chance. Low-key hoping there's no harem shenanigans in this one but we'll see.
You don't read much history, do you? Oftentimes, 13 was old enough to have considerable power over one's fiefdom, especially if you came from a powerful family and avoided becoming a ward.
I just checked translated parts of novel. And unless manga changed anything, then he is 16 years old, heroine is 16 years old, meido is 16 years old. And heroine mother's age is not given for some reason.
Anyway chapter two just came out and it seems sticking pretty closely to original webnovel, with maybe some minor, but interesting change. So I dare that those numbers probably still apply.
Anyway, for those who are interested there are some highlights that awaits us in upcoming chapters.
Heroine and her mother becoming protagonist's meidos too. (Main point of chapter 2)
Protagonist going to shopping and buying nice clothes for Heroine, her mother and meido too. (Likely main point of chapter 3)
Heroine and her mother both fully naked taking bath with protagonist. (Either ending of chapter 3 or beginning of chapter 4)
Why was the little sis obsess of conquering her brother look-a-like?And why was the brother helping her little sis conquer his look-a-like? Not just once but many more times