while doing homework, i found this super helpful website called 「反対語大辞典」, which translates to 'Antonym Dictionary'. its very useful when you know a word in japanese language but cant find the opposite of that word. for example i was looking for the opposite word for 帰国(きこく), and it is 出国(しゅっこく) the website link hantaigo.com JapaneseLearning