First, it's important to note that the distinction that you made between North and South Koreans didn't exist until after World War II and the end of the colonial period. At the time, Korea was simply Korea, albeit a colonized one.

The attitudes of the Koreans towards the Japanese was for the most part quite poor. Annexation was the final result of decades of Japanese involvement on the peninsula and was viewed as an embarrassment, as many felt that their national sovereignty was being severely violated. There were a handful of Korean students and scholars who wanted to embrace Japan and adopt its modernity in order to strengthen their nation so that they could be on par with other industrial nations. This was not a very common viewpoint, however, as the vast majority of Koreans simply resented the occupation. In "Under the Black Umbrella," (Hildi Kang, 2001) a collection of interviews about the colonial period (the interviews were done decades later, so while they are primary sources they are imperfect) many of the interviewees discussed the practices of the Japanese colonial government, which included spying on citizens suspected of dissent, forced Shinto practice, and the requirement that all Korean citizens speak Japanese, a requirement that was mostly enforceable only in schools, which young Koreans were required to go to.

As far as dissent goes, there was widespread active Korean opposition to the Japanese rule. The direct form would come in Korean rebels, many of whom actively fought the Japanese army, though they were largely and quickly wiped out. Other rebels, who would include Kim Il-Sung, would flee across the northern border into China, which following 1911 found itself in disarray. There they learned how to fight properly and, once the second Sino-Japanese War came into full swing, were even able to fight the Japanese again, although not in Korea. (Bruce Cumings, one of the best American authorities on Korea, asserts in "North Korea" (2004) that the North Korean army had an advantage in 1950 because many of its soldiers had fought against the Japanese.)

Following the initial violent opposition, however, Koreans attempted to win politically. Famously, they courted public opinion, and some even attempted to attend the Treaty of Versailles signing, not unlike Ho Chi Minh, in order to protest their illegal occupation. They would fail, although other nations, especially Germany, were stripped of their Asian colonial holdings. The largest protest that many cite is the March First Movement, with estimates of two million Koreans across the nation involved. In the initial protest, several students and scholars read off a Korean Declaration of Independence that used Woodrow Wilson's points about self-determination that had become popular at the end of the First World War. The protests were suppressed, often violently.

The requirements to speak Japanese, practice Shinto, and attend Japanese-run schools were all a part of the Japanese strategy of "Imperialization," which would assimilate the Koreans into proper subjects for the Emperor. This was also practiced in Taiwan and Okinawa, both Japanese colonies as well (although Okinawa would eventually be fully annexed and remains a part of Japan). The opposition to the Imperialization process was enormous. For many Koreans, it was outrageous to speak the language of their colonizers. The Japanese also attempted to give Koreans Japanese names, and while it occurred I'm uncertain about the scale of this undertaking. It was seen as an attempt to wipe away Korean culture, as Shinto shrines were erected in nearly every city and town. Other Koreans were distrusting of Japanese schools, which eliminated the Korean form of schooling that had become popular (although, perhaps to the credit of the Japanese, more young Koreans were being educated than before). Some Koreans who managed to succeed in their schools were allowed to study at the universities in Japan, and often were quite successful because of it.

When the war became fully underway, however, Japanese rule worsened. Korean men could be conscripted as either laborers or soldiers for the Japanese army. Some ended up in mines and factories, while others would be building airfields abroad. Others, still, would actually fight for the Japanese, and the reasoning here is quite odd. One of my professors was quick to point out that some Koreans volunteered for the army. Some would do it out of a sense of pride or a desire to "prove" themselves to the Japanese, although I don't think this should be interpreted as support for the colonial regime.

Overall, the view of the Japanese was quite poor and persisted well after the colonial period ended and, at the risk of sounding corny, actually remains of source of tensions between both Koreas and Japan. A good book to look at would be "Sources of Korean Tradition, Vol 2" because it contains writings that publicly opposed the Japanese rule.

Pre-1945 is a very vast time. Do you have a specific period in mind?