1917.（1910）Tongrip Chonsin, second edition:Shungman Rhee use the name of "Sea of Japan" in his textbook voluntary! it is NOT east sea!

Syungman Rhee, a stupid dictator and president of South korea who robbed Takeshima (Liancourt Rocks) illegally, his book "Tongrip Chonsin" second edition,

he use the attached map and it shows "Sea of Japan" in 1917.
*on second edition; March 27.1917. (first edition Mar, 1910)
He was in the United States and free from Japan at that time and he use the map with Sea of Japan instead of East Sea.

https://babel.hathitrust.org/cgi/pt?id=nnc1.cu51037017&view=1up&seq=55

This is from digital archives of Columbia University.