As the largest and most important ‘principal posts’ (yaku-bashira 役柱) in a minka, daikoku-bashira (大黒柱) will naturally be located fairly centrally within the structure, which could hardly be otherwise when you consider that the reason they are regarded as ‘principal’ in the first place is because they gather roof loads over a wide area. There may be more than one ‘principal post’ in a single dwelling, and whether or not these posts are considered to be daikoku-bashira, or some dialect variation thereof (as we will see there is a bewildering variety of alternative names), or some other type of ‘principal post’ entirely, seems to be a somewhat arbitrary or nominal matter, or at least to a large degree a matter of regional convention. Nor is there any specific structural role or configuration that one can point to as definitive of a daikoku-bashira, or as distinguishing or not distinguishing a daikoku-bashira from another type of yaku-bashira, other than that the size and structural importance of both set them apart from the ‘regular’ posts in the dwelling.

In a regular four-room (seigata-yon-madori 制型４間取り) layout, with the partitions between the raised-floor rooms arranged in a cross, there will usually be a daikoku-bashira at the intersection between the two rooms adjacent to the earth-floored doma and the doma itself; there may also be one at the centre of the cross where the four raised-floor rooms meet, and one in the doma. These principal posts are usually mortised to receive tenoned beams or lintels on all four of their sides; the roof loads are transferred via these beams into the posts. Because the beams usually all enter the post at the same height, the cross-sectional area of the post at this height is greatly reduced. To compensate, the post must be ‘super-sized’ well above that of a regular post so that even after mortising it is still strong enough to carry the loads expected of it. These posts are typically 20 to 30cm square, but posts of 50cm or more are not uncommon. Furthermore, whereas small-section posts are usually of conifer species such as Japanese cedar (sugi 杉, Cryptomeria japonica), Japanese cypress (hinoki 桧, Chamacyparis obtusa), or various species of pine (matsu 松 Pinus sp.), daikoku-bashira are usually made from stronger hardwoods such as Japanese chestnut (kuri 栗, Castanea crenata), Japanese zelkova (keyaki 欅, Zelkova serrata) or oak (kashi 樫, Quercus sp.), although in older houses large pine posts left in their natural trunk-like forms can also be found.

When placed in a line of smaller, normal-sized posts, such large posts will of course be much wider than the sills and headers tenoned into them. On the tatami-floored zashiki (the raised-floor ‘living’ area of the minka) side of the post, the corners of the oversized post will intrude into the corners of the tatami mats abutting it. One early solution to this was to make the tatami mats in a special shape, with a corner notched out to accommodate the post. This solution seems to have been disfavoured, giving rise to the inverse practice of instead taking a notch out of the post itself at the level of the tatami, and slotting a normally-shaped tatami into it. Alternatively, where the daikoku-bashira bordered the doma, a later solution was to shift the post off-axis towards the doma, so that the face of the post on the zashiki side was aligned with the sill and rail, though this could mean that the post might be loaded somewhat eccentrically. In any case, the method by which this problem was solved is one of the clues available to the architectural historian in trying to determine the age of a minka, or at least in establishing the general era in which it was built.

The *daikoku-bashira* is much wider than the sills and beams tenoned into it. In this case, the solution adopted is to shift the *daikoku-bashira* off its axes towards the *doma,* so that the faces of the post on the *zashiki* side are aligned with the inner edges of the sills, allowing the *tatami* mats to remain regular rectangles in shape. This method suggests that the *minka* is of relatively recent construction.

The plans below illustrate some of the different positions daikoku-bashira can take within different types of minka.

Three examples of the different positions *daikoku-bashira* can take in different *minka* types. The first plan is a regular four-room layout (*seigata-yon-madori* 制型４間取り) with three principal posts: one at the intersection of the four raised-floor rooms, one at the edge or the raised floor and the earthen-floored *doma* (どま), and one in the *doma* at the corner of the stable (*umaya* 厩). The second is a ‘divided ridge’ (*buntо̄-gata* 分棟型) layout, with a single daikoku-bashira towards the rear of the earth-floored ‘cookhouse’ (*kamaya* 釜屋) near the oven/stove (*kamado* 釜土), indicated as two circles inside a rectangle. The dashed parallel vertical lines indicate the box gutter between the two roofs. The third is a ‘Yamato ridge construction’ (*yamato-mune-zukuri* 大和棟造り) layout.

As mentioned, daikoku-bashira are most often, but not always, located at the boundary of the doma and the raised-floor ‘living’ rooms (‘A’ in the first and third plans above). There are many dialect variants for the name daikoku-bashira, including daigoku-bashira (大極柱 lit. ‘great-most post’), tatezome-bashira (建初柱 lit. stand-first post, ichiban-bashira (一番柱 lit. ‘number one post’), ichino-daikoku (一の大黒 lit. ‘number one daikoku’, and teishu-bashira (亭主柱 lit. head/master/husband post’. In the Chūgoku region, the daikoku-bashira enshrines the oven/stove (kamado 釜土) deity (kami 神) Dokujin (土公人), so it is called the rokkū bashira (ロックウ柱).

The ‘B’ posts that stand in the centre of the raised-floor section of the minka are variously called uwa-daikoku or ue-daikoku (上大黒 lit. ‘upper daikoku’), yokoza-daikoku (横座大黒 lit. ‘side sit daikoku’), ushiro-daikoku (後大黒 lit. ‘behind daikoku’), chо̄ja-bashira (長者柱 lit. ‘rich man post’), miyako-bashira (都柱 lit. ‘capital post’), ko-daikoku (小大黒 lit. ‘small daikoku’) ebisu-bashira (エビス柱 lit. ‘Ebisu post’; Ebisu is another of the Seven Gods of Fortune), naka-bashira (中柱 lit. ‘middle post’), etc.

The posts marked ‘C’ in the plans stand in the doma and ‘look across’ at the ‘A’ posts. They are often called niwa-daikoku (庭大黒 lit. ‘garden daikoku’; niwa is an alternate name for doma), shita-daikoku (下大黒 lit. ‘lower daikoku’, or umaya-daikoku (廐大黒 lit. ‘stable daikoku’; other regional variations are mukau-daikoku (向かう大黒 lit. ‘facing daikoku’), nirami-daikoku (睨み大黒 lit. ‘glaring daikoku’), ko-daikoku (小大黒 lit. ‘small daikoku), ebisu-bashira (蛭子柱 lit. ‘Ebisu post’), ushimochi-bashira (牛持ち柱 lit. ‘cow holding post’), etc. When the doma is deep front-to-back, there may be a second principal post in it, in the vicinity of the ‘fireplace’ (kajiba 火事場) near the back doorway (sekoguchi 背戸口); this post is variously called the mizu-daikoku (水大黒 lit. ‘water daikoku), kama-bashira (釜柱 lit. ‘oven/stove post’, or kо̄jin-bashira (荒神柱 lit. ‘storm god post’).　

A *daikoku-bashira* (here called a *niwa-daikoku* 庭大黒) standing in the middle of the *doma* (here called the *niwa* 庭). The beams tenoned into it support at least two mezzanine levels.

View of the cooking area of a *doma*. In the foreground is the *niwa-daikoku*, towards the rear is the *mizu-daikoku* or *kama-daikoku*. These posts support a mezzanine floor (*chū-ni-kai* 中二階) between them for storage.

In the ‘divided-ridge’ type (buntо̄-gata 分棟型) minka (where the living and cooking functions of the dwelling are separated into two structurally distinct entities, each with its own roof ridge) of the Tokai (東海) region, there is no daikoku-bashira in the living structure or ‘main house’ (omoya 主屋) part of the minka; that title is reserved for the principal post in the rear part of the ‘cookhouse’ or ‘stove house’ (kamaya 釜屋). In the minka of Yamato Kawauchi (大和河内), the ‘C’ post, called hanakami-bashira (はなかみ柱) is larger and more esteemed than the ‘A’ post. Some say hanakami-bashira is an alternate pronunciation of kamakami-bashira (釜神柱), but the name is more commonly thought to be a holdover from a time when living and cooking quarters were separated, as in the the aforementioned example of the buntо̄-gata minka, where the daikoku-bashira is in the cooking structure, and the post was in the rearward or ‘upper’ (kami 上) part of the ‘edge’ or ‘peripheral’ (hana 端) house, that is to say the cookhouse; therefore hanakami-bashira can be written 端上柱.