The true identity of Iwanaga-hime is the daughter of Oyamatsumi appearing at the end of Volume 1 of the *Kojiki* and in the 9th stage of the Age of the Gods in the *Nihon Shoki*^[1]. She is written as "Ishinaga-hime" in the *Kojiki*, and "Iwanaga-hime" in the *Nihon Shoki* and *Sendai Kuji Hongi*, with theories also equating her with Kokemusuhime and Konohana-chiru-hime. According to the semantic interpretation by Kokugakuin University's Classical Culture Project, her divine name means "a woman as eternal, steadfast, and enduring as a rock (Iwa)"—clearly designating her as a goddess symbolizing immortality, longevity, firmness, and solidity. Positioned alongside her younger sister Konohana-no-sakuya-bime as the two daughters of Oyamatsumi, she forms the core of contrast structures: "rock vs. flower," "eternity vs. transience," "solidity vs. beauty," "immortality vs. short life," and "rejected older sister vs. accepted younger sister."

The core of her narrative lies in the myth of the heavenly descent (Tenson Korin) found at the end of Volume 1 of the *Kojiki* and the 9th stage of the *Nihon Shoki*^[2]. After Ninigi-no-Mikoto (the heavenly descendant) descended to Takachiho in Hyuga, he met the beautiful Konohana-sakuya-hime at Cape Kasasa and proposed to her father Oyamatsumi. The father was overjoyed and presented both the older sister Iwanaga-hime and younger sister Sakuya-hime with many tributes. However, Ninigi rejected Iwanaga-hime for her ugly appearance, sending her back and marrying only Sakuya-hime. Oyamatsumi's lament became the story's climax—in the *Kojiki*: "If you had let Ishinaga-hime serve you, the lifespan of the heavenly descendants would have been eternally immovable like a rock; but because you kept only Sakuya-hime, your life will be short like the flowers of trees" (lifespan shortened due to the failure of Oyamatsumi's oath); in the *Nihon Shoki*: "Shortened lifespan caused by the curse of the unaccepted Ishinaga-hime" (a more direct causality). Though slightly different, both accounts serve as the origin myth for the shortened lifespans of humans and the imperial line, forming the foundation of Japan's indigenous view of life and death before Buddhism.

Comparative mythologist Tarō Ōbayashi classified this tale of contrast between Iwanaga-hime and Konohana-sakuya-hime as a Japanese variant of the "banana-type myth" (a tale of choosing between a stone and a banana)^[3]. Belonging to the same lineage as the origin myth of death from Sulawesi, Indonesia (where humans chose a delicious banana over a stone, losing eternity to gain a short life that withers in one generation), it is the Japanese equivalent of universal origin of death myths like the Book of Genesis (expulsion from Eden) or Greek mythology (Pandora's box).

Among her shrines, Kumomi Sengen Shrine (Kumomi 386-2, Matsuzaki, Shizuoka) garners attention in Shinto history and folklore studies as a rare shrine among the approximately 2,000 Sengen shrines nationwide that exclusively enshrines Iwanaga-hime. Sitting atop Mount Eboshi (elevation 162m), an ancient legend (recorded in the late 18th-century *Kojiki-den*) says, "When Mount Eboshi is clear, Mount Fuji is cloudy," historically identifying it as the older sister's seat in contrast to Sakuya-hime's Fuji. It was rebuilt in 1657, with its original founding unknown. Hoshoishi Shrine (Mikumo, Itoshima, Fukuoka) in the center of Ito-koku is an ancient shrine enshrining both sisters (recorded in the 1695 *Hoshoishi Shrine Engiki*). This rare sister-pair worship suggests a connection between imported continental culture and the Iwanaga-hime faith, given Ito-koku's role as ancient Japan's gateway to the continent.

Shiromi Shrine (Shiromi, Saito, Miyazaki; former Nishimera Village area) enshrines three deities: Iwanaga-hime, Oyamatsumi, and Prince Kaneyoshi (of the Nanboku-cho period)^[4], founded in 1489 with its original sanctuary built in 1675. Its sacred object is a "silver mirror"—a place-name origin legend claims the mirror Iwanaga-hime threw in despair over her looks caught on a tree on Mount Ryubo, changing "Shiromi Village" to "Silver Mirror (Shiromi) Village." As a symbolic equivalent to rock, the mirror shows the unique syncretism of Iwanaga-hime's rock worship and mirror deity worship. The 33-part Shiromi Kagura dedicated every December 12-16 is a National Important Intangible Folk Cultural Property, representing the pinnacle of Kyushu folk performing arts as the primary stronghold for modern Iwanaga-hime veneration.

Yui-no-Yashiro (Middle Shrine) of Kifune Shrine in Kyoto^[5] has been deeply worshiped for matchmaking since before the Heian period. Originating from the paradoxical legend that Iwanaga-hime hid in Kibune out of the shame of rejection, declaring "I will bestow good matches upon the people," she has been worshiped as "a god who does not sever ties, making them endure." The literary foundation for this matchmaking divinity is the story of Heian poet Izumi Shikibu (978?-1041?), who prayed here during marital strife and achieved reconciliation after dedicating a famous firefly poem. This paradoxical faith structure, linking the rock (a symbol of eternal immobility) with "enduring relationships," has continued unbroken from the Heian era to today.

In folk beliefs, Mount Omuro in Izu (elevation 580m) is seen as her incarnation, carrying a sympathetic superstition that "praising sister Fuji while climbing Mount Omuro brings curses of injury or poor fishing"—a classic example of folk empathy for the "rejected ugly sister." Furthermore, Mount Tsukuba's Gessuiseki Shrine (Tsukuba, Ibaraki) enshrines an Iwakura where Iwanaga-hime reportedly died, showcasing the blending of ancient Japan's rock worship with her divinity. At Oyamatsumi Shrine's precinct shrine, Anaba Shrine (Omishima, Imabari, Ehime), she is enshrined with her father Oyamatsumi, preserving the origin of father-daughter worship. Today, since Mount Fuji's World Heritage registration (2013), Kumomi Sengen Shrine and Mount Eboshi have become tourist destinations. Additionally, as the "sister rejected by beauty standards," she resonates with modern female readers, advancing a feminist re-evaluation. Frequently reappearing in modern media with themes of "immortality/solidity," "kindness behind ugliness," and "matchmaking," the modern reinterpretation of this ancient myth continues to evolve.