Second season of Tsukiuta. The Animation.

An anime about Operation Castle and the demise of the crew on the Daigo Fukuryuu Maru (S.S. Lucky Dragon 5). On March 1st 1954, a hydrogen bomb went off (that ended up being similar sized to the atomic bomb dropped on Hiroshima). The radioactive ash fell on the crew, poisoning them. The anime deviates into fantasy as the ash also affected the marine life--that talk and wear human clothing and is the main focus of the movie; how the radioactive ash affected the talking fish.

Part of Anime Tamago 2018.

A millennium ago, the Five Monarchs guarded the land of the Xia Dynasty with magical artifacts. Later, the leader of the Dragon Clan, Zu Long, assisted humanity by establishing the Yun Chui Empire. The Empire faces the Tranquil Ocean where the Xi and Black Water Clans have defended it throughout a peaceful millennium. Now, the waves are surging from below and chaos will rise once again.