Ihai (mortuary tablet) (位牌)

Ihai is a wooden tablet inscribed with the posthumous Buddhist name of a deceased person to enshrine the spirit of the person.

The tablet was named ihai (literally, 'rank' tablet) because it was considered to be the same as shinshu (a tablet inscribed with the official rank and name of a deceased person) used for Confucian funeral rites from the Later Han period in China. The origin of ihai is said to have come from the syncretization of the folkways of yorishiro (an idea in which a divine spirit resides in an object) and the sotoba (a tall, tower-shaped wooden tablet set up behind a grave for the repose of the dead) in Buddhism. Ihai was introduced to Japan along with the Zen sect in the Kamakura period and was widely spread in the Edo period.

Types of ihai
Ihai is generally categorized into three types: uchi-ihai (shiraki-ihai, or literally, plain wood ihai), hon-ihai (nuri-ihai, or lacquered ihai), and tera-ihai (literally, temple ihai).

Uchi-ihai
Uchi-ihai is a simple ihai made of plain wood which is inscribed with the posthumous Buddhist name, the secular name (name before death), the date of death, and the age at death (or to which paper inscribed with these is attached). No-ihai (temporary ihai) is created immediately after death and used for the temporary altar and the funeral. When a deceased person is buried, no-ihai will be placed over the ground until the memorial service on the forty-ninth day after the death or the decay of no-ihai itself. When a deceased person is cremated, no-ihai will be taken home and enshrined on a chuin-dan (a temporary home altar to enshrine the ashes until the memorial service on the forty-ninth day after the death and the interment ceremony). No-ihai is burnt after the chuin-dan is cleared (i.e., after uchi-ihai is created and the spirit of a deceased person is transmitted from noi-hai to hon-ihai).

Hon-ihai
Hon-ihai is an ihai created by the day of the memorial service on the forty-ninth day after the death to substitute no-ihai with. It is a gorgeous lacquered ihai decorated with gold leaf, chinkin (engraved design with gold leaf or powdered gold filled in grooves), or makie (design created by sprinkling gold or silver powder on the picture drawn with lacquer). Hon-ihai is to be enshrined in a Buddhist alter for many years to come. There are two types of hon-ihai: fuda-ihai and kuridashi-ihai. Fuda-ihai is an ihai inscribed (or engraved) with the posthumous Buddhist name(s) of one person or more such as husband and wife on the surface (the name of the person on ihai is inscribed in vermilion when he/she is still alive). There is a wide ihai for more than one person, called habahiro-ihai. Kuridashi-ihai is an ihai enclosing numerous wooden plates in a row, each of which is inscribed with the posthumous Buddhist name of a deceased person.

Tera-ihai
In addition to hon-ihai, an ihai called tera-ihai is presented to one's bodai-ji temple (family temple, also called danna-dera temple) or head temple together with donations for memorial services. At a temple, tera-ihai are enshrined in the ihai-do (hall for ihai) or the main hall and are prayed to during the devotional exercises of the morning and evening.

Ihai is categorized into two types: 'gyakushu-hai' and 'junshu-hai.'

Gyakushu-hai is an ihai created before death with the posthumous Buddhist name given before death.

Junshu-hai is an ihai created for a deceased person.

Ihai usually means Junshu-hai.

No-ihai
No-ihai is made of plain wood just like uchi-ihai. It is an ihai placed on a grave until the headstone is inscribed.

Differences between sects
Zen sect
The kanji character 'ku' (空, or emptiness) is added before the posthumous Buddhist name. The kanji characters 'shin-ki-gen' (新帰元, or newly returning to nirvana) are added on no-ihai, but they are changed to the character 'ku' on hon-ihai.

Shingon sect
The Sanskrit character 'a' (the first letter in the Sanskrit characters, 阿 in kanji) is added before the posthumous Buddhist name. The character symbolizes Dainichi Nyorai (Mahavairocana). For children, the Sanskrit character 'ha' (ka, or 訶, in kanji) is added before the posthumous Buddhist name. The character symbolizes Jizo Bosatsu (Jizo Bodhisattva).

Jodo-shu (Pure Land sect) and Ji sect
The Sanskrit character 'hriiH' is added before the posthumous Buddhist name. It symbolizes Amida Nyorai (Amitabha Tathagata).

Nichiren sect
The kanji characters 'myo-ho' (妙法, or esoteric Buddhism) are added before the posthumous Buddhist name.

Nichiren Shoshu
The kanji characters 'myohorenge-kyo' (妙法蓮華経, or the Lotus Sutra) are added before the posthumous Buddhist name. Hon-ihai are not created, and the name with the characters is recorded on the kako-cho (a home or temple register that records information about the deceased family members such as names, posthumous Buddhist names, dates of death, and so forth).

Jodo Shinshu (Shin Buddhism)
Jodo Shinshu except Shinshu Takada sect does not adopt ihai. Posthumous Buddhist names are recorded on kako-cho or homyo-jiku (a scroll inscribed with a posthumous Buddhist name).

In other sects, ihai has the meaning of a religious service, and also building a tower is considered to be a religious service. Creating ihai and building a tower mean the same (this applies to sotoba, too). Because the deceased are believed to have been already born in the Pure Land thanks to Amida Nyorai's primal vow (forty-eight vows) in Jodo Shinshu, the sect does not have the notion of eko (prayers for the repose of the soul) towards the deceased nor consider them to be objects of prayer. Accordingly, Jodo Shinshu does not adopt ihai. Ihai are created in some areas as a common practice; even in these cases, however, ihai, being used only for the record of a deceased person, do not have a special meaning such as an object where the souls of the dead reside as can be seen in other sects.

Children
The Sanskrit character 'ha' is often added before the posthumous Buddhist name. It symbolizes Jizo Bosatsu.

Size
The size of ihai is measured in the shakkan-ho (the system of measuring length in shaku and weight in kan). To measure the size of an ihai, only the fudatake (height of the flat tablet part where characters are inscribed) is measured and its size is represented in 'go'; for example, four go of ihai has approximately twelve centimeters of the fudatake. The sizes of hon-ihai are ranged from 2.5 to 7.0 go.

To measure the size of a large tera-ihai, however, the width of the flat tablet part is measured.

Numeration
Hashira (literally, pillar)

Production areas
Ihai are mainly produced in Aizu-wakamatsu (Aizu-ihai), Kyoto (Kyo-ihai), Nagoya (Nagoya-ihai), and Wakayama (Koya-ihai). Ihai produced in these areas are mostly high-end products.

Low-end ihai are produced in areas such as China and Vietnam.