Japanese uses syllabic characters (kana) along with the Chinese derived word characters (kanji). The syllabic characters are much simpler, consisting of only a few strokes, and are used for inflectional endings and other purposes, so they are quite frequent in written J. Compare the J and C examples on the Omniglot pp.

ONe of the commonest kana is "no", analogous in function to our "of", like a lowercase "e" reflected in a mirror and then rotated to the left so that the opening faces down: の . The angle of the cross-stroke can vary a bit. If you see that, you can be sure it's Japanese.

Here are a few more kana, selected more or less at random. Some are hiragana, others katakana; see wikipedia for details:

へ け さ フ ヒ サ