I've never seen the movie. I don't usually watch animal movies. I find most of them either disturbing or infuriating at some point, so it's just not worth it to me to watch them.

However, I will say, do NOT assume the laws are the same in Japan as they are here. It may be that they are, and the animals weren't hurt or stressed. However, it may be that they are NOT the same, and then you have no idea what actually went on filming this movie. I have no idea, nor do I wish to know, frankly. But assuming everything is sweet and rosy with an independent film made in a foreign country, which had to have scenes cut out to be shown in the US, seems a bit naive to me.