Should I be ashamed of my ancestor fighting the pacific front in WW2?

Shame on you!  Japan was the clear villain in WW2.

Good for him, sad for you... Now, go away.

Dumbass troll.  Just ignore the little freak.

The then Empire of Japan, was totalitarian, brutal aggressor in WWII. They invaded China (look up the "Rape of Nanking") and Korea. They attacked the US (Pearl Harbor) as a broader plan to allow them to take the Philippines and Solomon Islands as well as others. They would have attacked and conquered Australia if the US allowed them too. They were allied with Nazi Germany and Italy for no less than World domination!

Your Grandpa was fighting against Japanese Fascism and striking back at Japan for it's attack on the US (I'm assuming he was in the US Navy). He was fighting for no less than to keep the World free!  

The shame was on Japan to have set on this course of conquest! 

Why would you be ashamed of something that you were not even part of.  Frankly I would be proud of him.

What could you have done to prevent it?  Nothing?  fugetaboutit!!  We all know what happened to  the "great nation of japan", don't we?  Threw a blindside punch, turned around and ran home to LOSE!!

You should be ashamed for being an IDIOTIC TROLL.

there was Nothing Great in Japanese Officers eating Living Australian  POWS

I don't see how your grandfather fighting in any war, much less WWII, is shameful. I have Japanese ancestry and admire Japan, but imperial Japan was a brutal totalitarian state that was waging war on multiple countries in the Pacific, and they needed to be stopped. War is a terrible thing and should be avoided to the extent possible, but there's nothing inherently shameful in servicemembers doing what they've been called to do, so long as it's in accordance with the law of warfare.

No need to feel ashamed; you should be proud that he served after Jap an attacked the U.S.!