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 field trip takes the class away from the city for some summer fun, but when trouble occurs so far from home, there's no easy way to get to Junk.

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