There are a variety of reasons for Japanese imperialism & indeed a feeling of racial superiority was one.
The Japanese may borrow things from others but they in no sense regard themselves as inferior for that, if anything they are superior as they improve upon these things. The borrowal is also never complete, they are very pragmatic and only borrow what they think is of benefit to their national interest. If they think free market is best in one area they take up that, if they think state control is good in another area then they put that into action. Even prominent Japanese commies revered the Emperor & only advocated those aspects of Marxism that they felt would make Japan stronger. I can post more about Japanese political thought but its OT here.
These views of superiority have always had a strong undercurrent, they historically felt that they should take leadership of Asia which united under them would then take on the West. This seems to have been part of Hideyoshi's grand scheme when he invaded Korea & tried to invade Ming China, his plan was then to advance into India to get rid of the Portuguese.
Even prior to the Meiji restoration there were many Japanese thinkers advocating Japanese expansion to relieve the intense population pressure which were leading to famines and consequently the sins of abortion & infanticide (so said Sato Nobuhiro). At the same time Russia was threatening the northern shores & attacking the Japanese settlements in Sakhalin & Hokkaido. Sato said (in the 1820's) first Japan should open up to trade, centralize education, navy etc & then it should take over Kamchatka peninsula, Korea, Manchuria, in the South they should conquer Luzon & Java. Only this way could they put a halt to British plundering of Asia & stop the Russian threat, then it should conquer the rest of China, India which united under the Emperor would lead to the unification of the world under Japan (including the West).
When the Meiji restoration happened, these factors came into play because for the first time in recorded history the Japanese were the actual leaders of Asia and not playing second fiddle to China or anyone else because of the great sacrifices they made to catch up with the West. At the same time they saw that the West was rampaging all over the globe including in neighboring China, the Russian empire was making inroads into Manchuria & Korea which culminated in the Russo-Japanese war of 1904-05 & Russia's defeat. This exacerbated Japanese imperialism, some claimed that they should liberate Asia from the West & then take on the West (e.g. the socialist/Marxist patriot Ikki Kita) under Japanese leadership, of course most of these grand schemes were just in words & they just ended up replacing the Western imperialists with their own brand as far as the locals were concerned.
There were indeed brutalities in China but the Han are hardly in a position to pontificate as they have been even more ruthless imperialists throughout their history (most of PRC including many areas of Southern China were non Han but Hanized over the years through conquest, settlement, & genocide) which they are continuing today. It is a bit rich for them to complain about the "Rape of Nanking" from 75 years ago while committing the "Rape of Lhasa" today.
In their 1500+ years of recorded history, the external aggression periods were limited to Hideyoshi's invasion of Korea & the period between 1890s-1945. One may compare the Han & mleccha record with that.
Mlecchas are even worse, their historical record is abominable as is their current behavior (hey how come no war crimes tribunal for Bush & co for the invasion of Iraq?). As they won WW2 they fed the world an overdose about Nazi & Japanese brutality while covering up their own. Chacha Sam that beacon of "liberty" itself was founded on extermination of the natives & a long line of mleccha luminaries have justified their treatment of the natives including Thomas Jefferson, Ayn Rand, Teddy Roosevelt, Christopher Hitchens to name a few.
How many people know that it was that champion of "liberty" & worshiped as such by the Americans & their Indian fellow travelers who advocated "Indian removal"?
I am talking of course about Thomas Jefferson, his plan was for the US to take away native lands, the natives themselves would be induced to take up agriculture, Christianity, and assimilate. If they refused then they would be exterminated or pushed westward by the expanding USA. Andrew Jackson merely implemented his vision and gets all the blame. Check the total area of USA at its founding & check its total area today, those excess 7+ million sq. km's you think they got that through "freedom" spreading.
ctrl f Jefferson here:
http://manasataramgini.wordpress.com/20 ... dentities/
I don't think I have to repeat the British record here, the biggest criminals of them all & the most shameless liars too along with their Gunga Dins they left behind.
The world is always hearing about Auschwitz, Nanking but no one including Indians themselves talk about the British actions after they suppressed the uprising of 1857, think about why that is.
PS: The Japanese were very ruthless & thorough in their suppression of Christianity. A friend of mine's mleccha student was a missionary in Japan & failed miserably. He eventually apostatized & ended up becoming a biologist studying evolution, in their conversation he told him that the Japanese showed no defensiveness about their treatment of Christians including when figures such as Inoue Chikugo (an Inquisitor in Tokugawa Japan who prepared special tortures for Christians to get them to apostatize) were mentioned. Hindus by contrast would get apologetic about Shivaji's beheading of the four padres. Therein lies the reasons why Japan is secure & remains a land for the Japanese where as India is becoming a land for anyone but Hindus.
See:
http://vajrin.wordpress.com/2013/03/02/ ... or-hindus/