I don't know if these books caused any controversy in Japan, as they were published in 1989, but didn't get an English translation until 2013. The guy who wrote these books, Shigeru Mizuki, was a prolific manga artist in his time, but was only well known in Japan.

His work never saw official publication in the West until very recently in the 2010's, so we're pretty far behind in what information is available regarding his work.

the author, Shigeru Mizuki, is a beloved manga artist over in Japan, rivaling even Osamu Tezuka in popularity (depite him being unknown outside of Japan), so I assume it went over better than you might expect.
He also personally served in the Japanese military during WW2, where he lost his left arm, so he saw allot of things first hand