The Lamb

The one who's quiet, shy, and has a "soft" personality, meaning they don't hurt anyone, swear, commit crimes, and they might have some sort of harmless goal, like marrying the Hero or making the world a better place. This person is supposed to be cute because of all of these things. The Lamb is much more likely to be a girl than a guy and will never be an antagonist. They might isolate themselves from everyone else and won't talk in a loud voice as they are quiet. They use good manners and may sometimes over-apologize or be sorry for something even though they didn't do anything wrong.

The Lamb got their name from, of course, a lamb, an animal that you wouldn't expect to hurt anyone, acts a bit shy, and is found to be cute by many.

Examples of the Lamb
Naruto - Hinata Hyuga. She's the only one who truly cared for Naruto from the beginning even though everyone else in the village thought of him as an antipathy.