A love toy doll that is equipped with autonomous AI and behaves like a human being. They were forbidden to "love".
If you fall in love, the doll will be stupid. Still, they like someone. Is love a human privilege, or is it Science fantasy of dolls in love.

Suika is a cheerful 14-year-old who is growing a crush on her stoic but cute childhood friend, Yorozu. On the night where she has a literal brush with death, he rescues her and makes a very hasty proposal. Will she marry him!?

The promise with him.. will definitely bloom...

From MangaHelpers:
High-schooler Matsuzaka Satou has a reputation for being easy, but one day her lifestyle of sleeping with one boy after another comes to an end. It happens when she meets the child Shio, for whom she is convinced she feels true love for the first time. Satou may seem sweet and innocent, but there is nothing she won't do to protect their life together, including committing murder. But from where did she acquire the little girl, and how long can their "Happy Sugar Life" together last?

Included one-shot:
Volume 2: White Sugar Garden, Black Salt Cage (pilot)

Short story:
A short story was released in Young Gangan 23/24 of 2016 which is referred to below as 19.5. It was later released in Volume 6 as an extra.