Asian Painting

Found this painting at a local Goodwill , it is framed but was sitting with broken glass at the store ; no damage to the pith paper thank goodness. It is signed in lower right corner (pic 3) , going up the right side , does anyone recognize signature ? It is 22" by 26" framed , water color and paint ; image is beautifully done of horse and two men with the tree shading the water .Looks like they are traveling and came upon a watering hole to refresh the horse and cool down .
I will be replacing the glass , I don't want dust to ruin the painting or for it to get discolored from exposure . Japanese or Chinese ?