Japan subjugated the Korean Peninsula for the better part of a half century destroying their country and culture while raping their women and enslaving their men. They enslaved Manchuria, the Philippines, and as much of Asia as they could.
To be fair, the Koreans hate them, the Chinese generally do too, but a lot of that is latter day pot stirring for domestic politics. The Taiwanese rather like them, the Filipinos are willing to forgive with Christian charity, the Indonesians never really hated them, the Viets like them a lot better than they like the Chinese, and etc. It’s complicated.