How do you say little sister in English?

Cute girl example:

Little sister, a popular word on the Internet, started from the second element. The early meaning of the word "little sister" is the name of budding girl by fans, and it has a strict definition. For otaku, not just any royal sister or soft sister can be called "Little Sister". A girl must be gentle, lovely, beautiful and generous to be called "Little Sister".

The name "little sister" is quite implicit. Literally, it refers to female elders with little age difference. At first, the word was widely used to describe young girls with "budding", "small freshness" and "second dimension". It is said that girls need to be a little dirty to be cute. The appearance of essential stem of wind oil made "Miss Sister wants to go to heaven" popular on the Internet, and it also became a historic moment when the word "Miss Sister" began to be popular on the Internet.

The word "Little Sister" was first widely used on the Internet from LoveLive (the second idol project in Japan). Later, through the spread of barrage websites and animation forums, the "Miss Sister" of Er Yuan came into public view. At the same time, it also coincides with the prevalence of the phenomenon of "this baby". Babies are pleasantly surprised to find that calling others "Little Sister" and calling themselves "Ben Bao" have the same lovely attributes: they are smaller than Little Sister, so they are babies.