Type of Spiritual Experience
The mudras were applied to the kuji and is described in the Mikkyo teachings. The yamabushi ascetics of Shugendo used these hand/body gestures in healing and 'exorcism rituals'. Here we have a print where the mudra are being used.
A description of the experience
Shunsho – Lingering snow at the tea-house of the two eaves from eight views of Fukagawa 1769. British Museum. The area mentioned is an area noted for its ‘pleasure palaces’. In the picture you can see the use of the mudra
In the manga series Naruto, the use of hand seals substitutes for the incantations. Older Ninjutsu used both incantations and mudras. The hand seals are based upon the characters of the Chinese zodiac, which is a longstanding tradition in Japan, and Kishimoto used them specifically to draw upon that tradition.