This technique hardens the hair on user's head and shoots a multitude of hair senbon at the enemy. The sharpened points of the hair can turn the target's entire body into a pincushion.
When in Sage Mode, Jiraiya can use a senjutsu-enhanced version known as Sage Art: Hair Needle Senbon (仙法・毛針千本, Senpō: Kebari Senbon, English TV: Sage Art: Kebari Senbon). At the same time that Jiraiya kneads chakra and fires the hair needles, Fukasaku and Shima activate Jiraiya's hair roots, causing the hair to grow at an accelerated rate thus making limitless rapid-fire possible. The sheer speed of this technique makes it the fastest attack with the widest range in Jiraiya's arsenal. Jiraiya himself stating dodging this technique with speed alone is almost impossible and the only way to counter this technique is by blocking it.