Anra - Ara

...However, as we will see below, the Gaya states developed significantly in the second half of the 4th century, so it is safe to say that the Gaya states were established between the second half of the 3rd century and the mid-4th century.
[Late 4th century]
According to the Gwanggaeto Stele, around 400, there were many countries (Gaya countries) in this region, including Mimana Gaya (Gimhae) and Anra (Haman), and these two countries are the most representative of the region. They are known to have had a strong military force that could fight back against the invading Goguryeo army and to have had a fairly close cooperative relationship. These Gaya countries also cooperated with Wa (there are various theories that they were the Mimana Nihonfu, the Kita Kyushu government, or the southern coastal region of Korea) and were in conflict with Goguryeo and Silla.

*Some of the terminology explanations that mention "Anra" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…しかし次にみるように，4世紀後半の加羅諸国は大きく発展するので，3世紀後半から4世紀中葉にかけて加羅諸国が成立したとみてよい。
［4世紀後半］
　広開土王碑文によれば，400年ころのこの地方には，任那加羅(金海)や安羅(咸安)など多くの国(加羅諸国)があり，この2国が代表的な国で，侵入してきた高句麗軍に反撃するほどの強力な軍事力とかなり緊密な協力関係とがあったことが知られる。またこれらの加羅諸国は，倭(任那日本府説，北九州説，朝鮮南海岸地方説などあり)と協力して，高句麗，新羅と対立していた。…

※「安羅」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報