In Japanese syllabary, how many kana systems are there?

Kana are the two syllabaries that form parts of the Japanese writing system, contrasted with the logographic Chinese characters known in Japan as kanji: modern cursive hiragana; modern angular katakana; and the ancient syllabic use of kanji known as man'yōgana, which was ancestral to both hiragana and katakana.

Hentaigana are historical variants of modern standard hiragana. In modern Japanese, hiragana and katakana have directly corresponding sets of characters representing the same series of sounds.

Each kana character (syllabogram) corresponds to one sound in the Japanese language.