I was wondering if there are any journals, interviews, etc that focus on the Japanese soldiers who committed the atrocities in the Rape of Nanjing. Maybe they shouldn’t have been given any attention because of how brutal and awful they were, but I was just wondering how it may have been attempted to be justified, like how Hitler justified his own atrocities.
Short answer:
There's a great deal of material. Much more if you can read Japanese, but still plenty available in translation.
Discussion:
There's the famous memoirs of a Japanese soldier who was there, Azuma Shirō, these were originally published in Japanese, the original title translated into English is "My Nanking Platoon: The Nanking Massacre Experienced by a Conscripted Soldier". These have been translated into English and are widely available. Azuma is apologetic, but the Japanese generally haven't been, and Azuma was sued for libel by his officers for his account of the Nanjing Massacre, and was found guilty in 2000. He had (he died in 2006) both supporters and detractors in Japan.
Japanese memories of the Second World War are of great brutality, including great brutality to conscripted Japanese soldiers and the Japanese population; given the magnitude of their own suffering, very generally popular sentiment has not tremendously interested in the suffering of others at their military's hands. There has been a consistent pacifist and anti-militarist movement in Japan since the War; these people are much more ready to engage these issues, but the prevailing LDP business establishment hasn't been much interested. You can think of it as being about the level of interest you'd find concerning My Lai in the US.
Nanjing has famously been described in Japanese accounts as a military advance into a chaotic situation. It happens to be one of the most celebrated of Japanese war crimes in China, but that's principally because there were Europeans there who documented it. The "bandit suppression operations" in Manchuria were of comparable brutality, and are rationalized as anti-guerilla operations.
You can find extensive discussion of just what Japanese textbooks say on the issue-- school textbooks are a contentious matter in both Sino-Japanese and Korean-Japanese relations. Koreans and Chinese examine Japanese history textbooks with great care, and object strongly to attempts to diminish Japanese behavior in them.
Sources:
Oshiba, Ryo. “Globalization and Education in Japan: The Case of Junior High School History Textbooks.” Fairness, Globalization, and Public Institutions: East Asia and Beyond, by Jim Dator et al., University of Hawai'i Press, HONOLULU, 2006, pp. 286–299.
Schneider, Claudia. “The Japanese History Textbook Controversy in East Asian Perspective.” The Annals of the American Academy of Political and Social Science, vol. 617, 2008, pp. 107–122.
Azuma, Shirō. "The Diary of Azuma Shiro" Jiangsu Education Press (2006)
Morgan, Raleigh. “Chinese, Japanese, and United States Views of the Nanking Massacre: The Supreme Court Trial of Shiro Azuma.” American Journal of Chinese Studies, vol. 9, no. 2, 2002, pp. 235–246.