|This is the article on secret techniques. For light novel series, head to Naruto Hiden.|
Hiden (秘伝, Literally meaning: secret tradition) or simply "secret" techniques are passed down from generation to generation in certain regions or clans.
The groups who possess these techniques are usually extremely secretive about them in order to ensure that no one other than the members of the group or clan learns them. As such, they are passed down through oral means instead of being written down or recorded. A few hiden techniques require a special ability or lineage and as such are usually the pride and fame of the clan that possesses them.
Many hiden techniques are rooted in Yin or Yang Release such as the Nara clan's Shadow Imitation Technique, or, the Akimichi clan's Multi-Size Technique respectively. These techniques cannot be copied through simple observation, however, they are not to be confused with kekkei genkai, as technically, hiden techniques can be taught to anyone.