samurai's european paintings

My friend and I were still in Kakunodate town known as well preserved samurai's houses. In here, I heard later that besides samrai's houses, there was another samurai's heritage, which was called "ran-ga", European paintings. Especially, the paintings made by the samurai around this area were called "Akita ran-ga". Akita is just now the prefecture's name, and in the edo period (from around 1600 to 1860's), it was the name of the fief of the feudal lord.
The feudal lord in Akita was the house of "Satake". Maybe, one of Mr Satakes in a middle of edo period, liked painting, at first Japanese style, then European's. He knew European paintings from his samurai, Mr Onoda who learned European paintings from imported books, and favored them. So, we can now find well-preserved samurai's European paintings around Akita area, and a library in Kakunodate town seemed to be known as the one having some Akita ran-ga.
By the way, in term of ran-ga, "ran" means "Netherlands", and "ga" means "painting" (therefore, to say literally, ranga means just Netherlands style painting. Of course, ran-ga is European painting as a whole, actually). This is because Netherlands was one of few countries that could trade with this country.
So, how's the samurai's European paintings?
Sorry, I actually missed them 'cause the library was closed at the time, and never have a chance to enjoy them.
Here was Kakunodate town, Japan