Also inzō 印相 also read insō, shu-in 手印, and mitsu-in 密印. Sk: mudra. A hand gesture that symbolized the special characteristics of a Buddhist deity. Iconographically, the term in (or mudra) generally means the hand gesture of a Buddhist image, although the same term is also used for the hand gesture of a worshipper. Sometimes, the iconographical mudra and worshippers hand gestures are not identical. In also includes the objects held *jimotsu 持物 by a Buddhist image, which symbolize the identity of the image.
The origins of the mudra in Buddhist iconography have been traced back to Gandharan Art. An early example is the *shokuchi-in 触地印 (Sk: bhumisparsa mudra) which symbolized the Buddha's victory over the demons who tried to obstruct his final enlightenment. In the same way, the prototype of the *tenbōrin-in 転法輪印 (Sk: dharmacakra mudra) is found in the image symbolizing the Buddha's first sermon at Sarnath.
Mudras developed gradually in India and were finally fully systematized when incorporated into Esoteric Buddhism mikkyō 密教, from about the 5th century onward. The mudras used in Japanese Buddhist iconography are basically the same as those used in Mahayana art in other Asian Buddhist countries but have localized to some extent. As regards the iconography of *Shaka 釈迦 (Sk: Sakyamuni), tradition shows him displaying the *semui-in 施無畏印 (Sk: abhaya mudra) with his right hand and *yogan-in 与願印 (Sk: varada mudra) with his left hand. On the other hand, the so-called Vajrasana style, in which the seated image forms the shokuchi in with the right hand and *zenjō-in 禅定印 (Sk; dhyana mudra) with the left, is frequently found in images of Shaka in Asian countries, but in Japan it is rarely used in the iconography of Shaka, and is found instead in images of *Ashuku 阿しゅく (Sk: Aksobhya).
Similarly, *Amida 阿弥陀 (Sk: Amitabha/Amitayus) in Japan, just as in many other Buddhist countries in Asia, forms the zenjō in with both hands, but the left hand is slightly different from the right. Amida's mudra in Japan is called *mida-no-jōin 弥陀定印, and that used in other countries is commonly called *hokkai-jōin 法界定印; the latter is found in Japan mainly in images of *Dainichi 大日 (Sk: Maha vairocana) related to the *Taizōkai mandara 胎蔵界曼荼羅 (Major mudras) in Japan and their related Buddhas are: Shaka, semui-in (right hand) and yogan-in (left hand); Amida, mida-no-jōin tenbōrin-in, *Amida kubon-in 阿弥陀九品印, and *raigō-in 来迎印; Dainichi, *chiken-in 智拳印 and hokkai jōin.