Yuta and his friends attempt to unravel the mystery of the city and everyone else's memories. However, more questions arise when a strange samurai arrives and tries to tamper with Gridman.

A few unexpected encounters leave Yuta and the others in shock. Except, Gridman being hunted down means Yuta is ever in danger.

When the Tsutsujidai High School Festival is threatened, the Gridman Alliance must decide how to proceed. Some of them wonder if fighting is the only choice they have.

Akane tries to win over the Gridman Alliance by lulling them into a dream. Will they remember each other and Gridman's calling or forever have sweet dreams?