Help finding game

The description sounds a bit generic;
You might be able to find it if you remember what one character looked like, for instance if you know what the sister looked like and if she was younger or older, you just search on vndb on left side under character traits. There you can use the Search Traits on top to search for a certain tag like for example school, imouto (little sister),etc. or use below the Trait Tree and you will be able to go here with imouto for example https://vndb.org/i958

Then you enable grid view on right side to see the character pictures and just browse through till you find what you are looking for.

And if you remember something like for instance her hair color you can add that to the search and press search button below to filter.


Of course you can also use the search function on the left side in the menu for tag searching the visual novels, might be easier if you remember the cover of the visual novel. Typing there under Tags imouto gives you this https://vndb.org/g3203
Also its advised to have an account on vndb so you see nsfw pictures (you can set it under settings) if you dont have one yet.