Answer: Japanese
Step-by-step explanation:
The languages spoken in the world today mostly seem to have a greater family group that they come from for instance most of the languages spoken in Europe come from Latin on account of the Romans having conquered most of the continent.
Some scholars don't think this to be the case for Japanese. They argue that the Japanese were mostly isolated from the rest of the world for a long time and so their language evolved on its own without much influence from a greater language group.