雷電 らいでん Raiden
Iwanai, Shiribeshi region, Hokkaidō
Ainu spellings: Ray-ni, Ra-enrum, Raenpet, Kamuy-ru-oma
Raiden is written with characters meaning thunder and lightning, and the Japanese name is old enough that the Edo-period maps already write it, some as 来年サキ. The Ainu-side names recorded along this coast — ライニ, ライルム, ラエンベツ, カモエルヲマ — belong to different points, and which of them the Japanese name came from is what the readings disagree about.
Location
42.9036, 140.4696 · Coordinates: OpenStreetMap Nominatim, 2026-09-10, on 雷電山. Open in OpenStreetMap
Referents
- settlement The Raiden district of Iwanai, no longer a registered address and now part of Shikishimanai; the stretch of coast west of the Shikishimanai harbour and the Narukami tunnel, some 10 km long, with no resident population. It once had a primary school and, later, a hot-spring resort, all of it now derelict.
- cape Cape Raiden, with the Katanakake rock at its point.
- river The Raiden River, and on 伊能大図 the neighbouring Raini River, now the Oyakobetsu.
Analyses
ray-ni
ライニ ‘dead tree’ received readingProponent: 永田方正 (Nagata Hōsei)
Nagata's entry reads 「Raini ライニ 枯木 往時枯樹林あり故に名なづく」, a stand of dead trees in earlier times.
Objections
- ray-ni names one dead tree. Compounds like rayni-us-i 'place of many dead trees' or ray-ni-tay 'dead-tree wood' would be possible as names; a single dead tree as a name has no parallel the author has seen. Dead trees are everywhere and do not last, which makes a poor landmark, and after more than 250 years the tree itself could not be checked. Observation on the ground found nothing remarkable about dead trees or driftwood there. — zenibako_trek zenibako_trek…
ray and ni are dictionary words and the compound is ordinary. The name of a single dead tree is offered without a parallel, and the referent cannot be checked.
ra-enrum
ラエンルㇺ ‘low headland’ proposedProponent: 知里真志保 (Chiri Mashiho)
Cape Raiden, with the Katanakake rock, is not a low headland, so the reading is referred instead to the cape before it, shaped like the toe of a boot, which has no name of its own and is called Yūnai-zaki here. ライルム does turn up as a name in the old journals and maps.
Objections
- The position of ライルム is fixed and it is far to the west, beyond the Shiribetsu River, around Shimakotan in Isoya. It is too far from Cape Raiden to be the same name. The Raini River on the other side is much closer. — zenibako_trek zenibako_trek…
Both parts are dictionary words. The name they explain is recorded at a place far from Raiden, and the step to ライデン is a long one.
らいねん
ライネン ‘'next year', the parting word of Yoshitsune’ proposedProponent: 岩内観光協会
In the pamphlet's telling, the chief Chipa's daughter Menuka loved Yoshitsune, who wintered here and on leaving in spring promised 「来年はきっと帰ってくる。来年まで」; the name is said to be a worn-down form of that word. Menuka is said to have thrown herself into the sea from Cape Raiden, and a cave is shown for it.
Objections
- Legendary anecdotes of this kind are told as tales about names, and this one, with the Yoshitsune arrival it depends on, is a later invention. Stories of Yoshitsune and an Ainu woman are past counting on the west coast. — zenibako_trek zenibako_trek…
A Japanese word attached to a legend, with no Ainu material behind it. It does record that the cape was called ライネン, which the documentary spelling 来年サキ confirms.
kamuy-ru-oma
カムイルオマ ‘the god's road is there’ proposedProponent: 小学館 日本大百科全書（ニッポニカ）
The encyclopedia entry for the Raiden hot spring gives the name as a worn-down kamuy-ru-oma, or else as ライニ. The reading appears to come from Matsuura's map, where カモエルヲマ is annotated with the note that the Japanese say ライテン.
Objections
- The 西蝦夷日誌 lists カムイルー and ラエンベツ as two separate places in the same passage, so Kamuy-ru-oma and Raiden are different names. — zenibako_trek zenibako_trek…
Every part is a dictionary word and the name itself is well attested nearby; what fails is the identification with Raiden, which the source that carries both names contradicts.
raenpet
ラエンベツ ‘the stream written ラエンベツ, taken as the source of the Japanese name’ proposedProponent: 松浦武四郎 (Matsuura Takeshirō)
Matsuura writes 「ラエンベツ（小川、出稼）和人ライデンと訛り、今雷電の字を用いゆ」: the Japanese made Raiden out of Ravenbetsu, and the characters 雷電 followed. He gives no segmentation, and the article does not divide the name; the author takes ラエンベツ to be the present Oyakobetsu River.
The record names a stream and the Japanese form derived from it, without saying what the Ainu name means. No source divides the name.
ray-ni-an
ライニアン ‘there is a dead tree’ proposedProponent: zenibako_trek（小樽銭函地名歴史研究会） (zenibako_trek (Otaru Zenibako Place-Name and History Society))
The author keeps Nagata's dead tree and changes what it is. At Eino-hama, the beach that 今井測量原図 marks as ラエニ, a single rock stands beside the old road, the Kasa-iwa, which from a distance looks like a dead tree standing there. A rock does not rot, which is what a landmark needs. From ray-ni-an the author derives ライネン, the form the Edo maps write 来年, and from that ライデン. The route to the rock leaves from the free parking area 敷島内 風の駐車場 between the Raiden and Benkei tunnels, where a signboard for the Kasa-iwa stands; the old road itself is gated shut, and the way down to the beach runs beside the gate over 250 m of loose stone.
Evidence
- documents
ライニ is marked as a place name on 伊能大図, on 今井測量原図 and on the prefectural survey map of about 1892, and 今井図 separates it from the river ラエニベツ.
- topography
The Kasa-iwa still stands at the marked spot, conspicuous on an otherwise plain stretch of stone beach.
ray, ni and an are dictionary words and the phrase is grammatical. The identification of the dead tree with the Kasa-iwa is the author's reading of the rock's appearance, and how long the rock has stood is unknown; the chain ray-ni-an to ライネン to ライデン is offered with a hedge.
Attestations
- 来年サキ map 1808 蝦夷国輿地全図
The 附図 of the 津軽一統志 of An'ei 5 also writes the cape 来年サキ, so ライネン was a real way of saying the name.
zenibako_trek… - ライニ川 map Edo period 伊能大図
The present Oyakobetsu River. The stretch by the Kuruma-daki, next to the Raiden River, is written ホンライニ.
zenibako_trek… - ラエニ map Tenpō era 今井測量原図
今井図 gives the position of ラエニ separately from ラエニベツ, the present Oyakobetsu; the spot is the beach locally called Eino-hama. 明治25年頃の道庁実測切図 also marks ライニ.
zenibako_trek… - カモエルヲマ map Edo period 東西蝦夷山川地理取調図
Matsuura writes beneath it that the Japanese call it ライテン.
zenibako_trek… - ラエンベツ document Edo period 西蝦夷日誌
カムイルー ヤマイ（岩平、七町）、ラエンベツ（小川、出稼）和人ライデンと訛り、今雷電の字を用いゆ。
Kamuy-ru and Raiden are two separate names in the same entry.
zenibako_trek…
Related names
- 傘岩 かさいわ — The standing rock at Eino-hama that the author takes for the dead tree of the name. Once a sightseeing spot, now behind a gated stretch of old road. zenibako_trek…
- 二ッ岩 ふたついわ — On the way to the Kasa-iwa, with a hole near the top that looks like an eye. The Ainu name is ウカヲフ, which the author reads as ukaw-p 'the place where the rocks pile on one another', with a hedge. zenibako_trek…
- 湯内 ゆうない — yu-nay 'hot-spring stream'. The Raiden hot spring was opened on its upper course for travellers on the Raiden mountain road; steam from it was visible from ships, according to the 観国録 of Ansei 3. zenibako_trek…