[1] Currently, most scholars agree that the Japonic languages were brought to the Japanese archipelago between the 7th and 3rd centuries BC by wet rice farmers of the Yayoi culture from northern Kyushu, replacing the indigenous Jōmon people.

According to her, the Insular Japonic languages entered the archipelago around 700 BC, with some remaining in the southern Mahan and Byeonhan confederations.

One theory suggests that when taking into account innovations in Old Japanese not shared with the Ryukyu languages, the two branches must have separated before the 7th century,[8] with the Ryukyus migrating from southern Kyushu to the Ryukyus with the expansion of the Gusuku culture around the 10th–11th century.

[10] Robbeets proposes a similar theory, but places the separation date in the 1st century BC.

Vovin classifies the Tamna language as part of the Insular Japonic branch.