For centuries, there has been a war between humanity and the Nighlocks, creatures who emerge from the depths of the underworld and cause fear and terror to those around them. To fight against these creatures, the Emperor of Japan ordained five clans of samurai around the world to fight against the Nighlock threat three-hundred years in the past, forming the Samurai Strike Power Rangers. These samurai possess the abilities of "Symbol Power", which allow for them to manipulate the kanji (Chinese characters) of the Japanese language to draw upon abilities and ordain themselves with the elements to fight the threats. They likewise utilize "origami zords" to fight against these creatures "second life", which turns them into giants which rampage through the nation.
For 17 generations, the war between the Power Rangers and Nighlocks continued, with slight reprieve given due to a massive sacrifice of the former leader to temporarily stop the Nighlocks leader, Lord Drakon. However many years later, with the Nighlocks beginning their attacks again and Drakon rerising to flood the world with the water of the Sanzu River of the underworld, Takeru Shiba, the 18th Shiba Clan leader, must gather his retainers again to fight back against the threat and protect the world. However, as this generation faces the toughest threat from the Gedoshu yet, a dark secret may cloud over the Rangers as the war rages onwards.
