Off-topic: websites I read in sequence this a.m.

First was Masahiko Amakasu bio in wikipedia:

In 1940, Amakasu produced Shina no yoru ("China Nights")....the film told the story of a Chinese woman Kei Ran whose parents had been killed in the war by a Japanese bombing raid and was violently anti-Japanese as a result. A handsome and caring young Japanese naval officer Tetsuo Hase falls in love with her, but she resists his advance until he violently slaps her face, despite her tears and begging him to stop, and after which she declares her love for him. After being slapped into declaring her love, she apologizes for anti-Japanese statements, and in a true Pan-Asian union, the two are married and lived happily ever after. The film was and still is very controversial in China, with most Chinese feeling especially humiliated by the face slapping scene with its suggestion that all one has to do is slap around a Chinese woman to make her love one. The Japanese historian Hotta Eri argued the cultural nuances of Shina no yoru were lost on Chinese audiences. In Japan....both the Imperial Japanese Army and Navy, officers routinely slapped the faces of the men under their command when giving orders, which was portrayed not as an exercise in petty humiliation, but as an act of love, with His Imperial Majesty's officers acting as the surrogates for the Emperor, who had to discipline his "children" by having their faces slapped all the time.

Then from World War II Today (fantastic website btw) on the treatment of POWs in Nagasaki:

Another problem was dropsy (an accumulation of water in the tissues), and in these cases numerous trips to the toilets became a necessity, especially at night.

Those who made the lavatory trip were usually in a great hurry but first the permission of the guards on duty had to be obtained. POWs had to bow and say ‘Banjo-ari-ma-sen’ (Toilet please). On the return trip another bow to the guard was required and an ‘Arigato’ (Thank you).

Some of the guards were bloody-minded and instead of allowing the man straight through they kept him waiting for no apparent reason. This delay was sometimes disastrous. The result caused great amusement for the guard and also earned the unfortunate man a few slaps on the face.

The argument that slapping=love seems a bit weakened.