Kokone Morikawa has a strange napping disease that distracts her from reality, one that makes the world of her dreams and the real world near indistinguishable. In reality, she is an average high school student preparing for her university entrance exams; but in her dreams she is a magical princess of Heartland, a machine-driven future where the use of artificial intelligence is forbidden. Within the seemingly imaginary dreamland, Kokone discovers more about her family's past and the secret that her father, a talented mechanic, has tried to protect her from. However, as the events between two worlds intertwine, she must now protect the secret from villainous entities, both dream-like and terrifyingly real.

Kotetsushin Jeeg takes place fifty years after the original and features a new cast of characters—primarily the new main character Kenji Kusanagi, a high school student who becomes Kotetsushin Jeeg to fight the sudden reappearance of "Haniwa Genjin" ("Haniwa Phantom Gods", or clay robots) from the Jamada Empire ruled by Queen Himika. Other characters include Tsubaki Tamashiro (grandaughter of Miwa Uzuki); and Kyou Misumi. Other main characters from the original series also appear.

A contest is made by the Fifth Hokage called Jonin vs Genin. The point is to collect crystals for points, with the higher-ranked Chunin and Jonin holding crystals worth more points. The Genin have blue crystals, while the Chunin and Jonin have red crystals. The video shows various fights between the Genin and Jonin, which each instance ending in the Jonin unknowingly losing their crystal (or discarding it). (Source: Wikipedia)

The story is set on Okinawa's isolated island of Iwado, which has seen a growing movement advocating a return to an autonomous government. Ao Fukai, a 12-year-old boy with a missing father, lives on the island with an old doctor named Toshio and is about to enter middle school. Ao's mother was taken away a decade ago by unknown individuals. Naru Arata, Ao's 12-year-old childhood friend and the story's heroine, lives with her father, older sister, and grandmother. She has a "Yuta" power awakened within her due to an incident when she was young. A mysterious entity called "Secret" suddenly appears and launches an attack on the Scub Coral lifeform on the island. Ao launches a certain military FP called "Nirvash" aboard a Japanese military transport in his fervent desire to protect the island. (Source: FUNimation)