What uchikorobi is
Uchikorobi sets posts to lean slightly inward instead of standing upright. The structure narrows towards the top, which makes it look settled when seen from below.
Shrine gateways use it. The approach gateway at Kasuga Shrine in Oita Prefecture, built in 1720, is described as a stone gateway 3.1 metres wide and 3.8 high, its round posts set on footing stones leaning inward and tied by a tie beam and two lintels, with a strong upward sweep at the ends of the top lintel giving it a forceful elevation.
The west gateway at the same shrine, built in 1934, has posts 36 centimetres across set the same way, its lintels of near-equal depth and curved throughout, which the entry says gives it a settled appearance. That word states the purpose of the technique.
Bell towers use it too. The bell tower at Nyoiji in Aichi Prefecture, from about 1755, is described as Irimoya-zukuri and pantiled on a stone platform, its square posts set on footing stones leaning inward and tied by three levels of beams under a bearing plate, with projecting brackets, Kaerumata between them and a gable of Kōryō and Taiheizuka.
Where it is not used
Records also note its absence. The hall at Tomobayashi Shrine in Osaka Prefecture, built in 1940, is described as built of unpainted timber with heavy members, its Munamochi-bashira standing upright without any lean. The absence is worth recording because the lean is the norm.
It tells most on open structures. Gateways, bell towers and gates without walls have nothing but their posts to give them an outline, so the angle of those posts decides the effect.
On site, look up along the posts. If the gap between them narrows towards the top, the lean is there. On a stone gateway, comparing the width at the footing stones with the width beneath the top lintel makes it plain.
It is not the same as the curve of a stone wall. That curve shapes a surface; this angles a member, and the two work on different principles.
References
- Agency for Cultural Affairs: National Treasures and Important Cultural Properties (structures)
- https://www.bunka.go.jp/seisaku/bunkazai/shokai/yukei_kenzobutsu/kokuho_bunkazai.html
- National Cultural Properties Database: Kasuga Shrine approach gateway, its round posts set leaning inward
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009095
- National Cultural Properties Database: Kasuga Shrine west gateway, posts 36 centimetres across set leaning inward
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009096
- National Cultural Properties Database: Nyoiji bell tower, square posts set leaning inward on footing stones
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009465
- National Cultural Properties Database: Tomobayashi Shrine hall, with crossed finials, billets and upright ridge posts
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00014272
Last verified: 2026.09.10