Keizo Koyama ( 1897 - 1987 ) was a Japanese painter. Keizo Koyama s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 558.66 USD for Mt. Asama in 2009 to a remarkable record 1117.32 USD for Mt. Asama in 2009 , based on the size and medium of the artwork.