Sorry but I have to correct some things here...

Has Japan had a Civil War? No.
Wrong. Japan's history is filled with civil wars, both large and small. The last being the Boshin War from 1869 to 1869.
Has Japan had a 9/11 incident? No.
You wouldn't compare the atomic bombings and firebombings as the same as the 9/11 incident. If anything, what the Japanese experienced was far worse than the petty 9/11 incident.
Has Japan ever had a war between religious groups (like the UK's Williamite Wars or the Crusades)? No.
Are you kidding me? WWII was basically a religious war for the Japanese. As well as that, the Tokugawa Shoganate banned Christianity in 1614 and killed anyone who was thought to be Christian, thousands died. As well as that, there have been mass slaughterings of buddhists all throughout Japan's history.
Has Japan ever enslaved blacks, white, native americans, and/or any other "foreign" groups? Not to my knowledge.
There has been slavery in Japan, but not to the extent of other countries, and certainly not of foreign groups. However, during the Second World War the Japanese army did use captured POWs for slave labour.
I've had the sad experience of Brits and Swedes telling me to my face that I was an anomaly because I am racially mixed.
I'm sorry you had to hear that.