Nisetsumuri (Fake Snail) is a side character in Sumikko Gurashi with a certain circumstance. As the name suggests, it is not actually a snail; its true identity is a slug. It wears a shell to mimic a snail and always feels a bit guilty. So whenever something happens, it quickly apologizes due to its guilt, displaying a humble character.

However, the secret is actually known to the surrounding Sumikko Gurashi characters, and despite that, they all treat it kindly and are good friends with it.

The closest friend is Tokage. Tokage is actually a dinosaur, so they're both individuals hiding their true identities (Fake Snail knows Tokage is a dinosaur), and they naturally get along well. Since the shell is a disguise, it often forgets it, or switches it for a different pattern.