Japanese has three alphabets (and the English alphabet… and those Arabic numbers we are all familiar with)

• Hiragana (ひらがな) for native words, grammar, and morphology - it reminds me of cursive
• Katakana (カタカナ) it gives an unmistakable clue you are reading a foreign word - but can also be used for emphasis
• Kanji (漢字) borrows Chinese characters that can be read with native or borrowed sounds, but generally with the same meaning

Given those and the English letters at your fingertips they have a lot of tools to give context. Grab a newspaper or Manga sometime, even if you don’t know the words you can tell each writing system apart pretty easily.

“Hurd OS? Isn’t that obsolete?” “Not obsolete. Just… illegal.” ~Rainbows End by Vernor Vinge