What term refers to the written characters used before kanji?

Question

The kanji characters were borrowed from China, so what were the written language characters called before kanji was introduced?

Answer 1

The generally accepted view is that there was no pre-kanji written script in Japan.

There are occasional claims of the existance of pre-kanji scripts called [神代文字]{じんだいもじ}. As the wikipedia page mentions:

Some have claimed since the mid-Edo period that such ancient characters, for example such as Chikushi characters and Hokkaido characters, have been found in archeological remains, in Kofun and on mountains, but all jindai moji are generally considered to be forgeries.