In the 1700's, Crown Prince Lee Sun fights against Pyunsoo hwe. Pyunsoo hwe is an organization that has accumulated power and wealth through privatizing water all over Joseon. Crown Prince Lee Sun becomes a hope for the people who suffers. Ga-Eun is the woman Crown Prince Lee Sun loves and she helps him grow as a ruler.
|Title||Ruler: Master of the Mask|
|First Air Date||2017-05-10|
|Last Air Date||2017-07-13|
|Episode Runtime||00 Hours 35 Minutes|
|Total Episode(s) on All Seasons||40|