Why did the Battle of Thermopylae become legendary? The Greeks won a surprise victory, and the Persians retreated.
The battle caused the Peloponnesian Wars between Athens and Sparta.
Dozens of Spartan warriors held off the entire Persian army for three days.
A Greek navy led by Themistocles trapped and destroyed the Persian navy.

Dozens of Spartan warriors held off the entire Persian army for three days.

Explanation:

Battle of Thermopylae became legendary among the Greeks.  Three hundred Spartan warriors set up defenses in the mountain pass.  A sheer cliff protected their left, and the sea was on their right.  They held off the Persians for three days.  The Persians went on to burn Athens

i'd assume india mainly because of how isolated japan was.   plus it is a whole china away.