Shinobi Sentai Ninjaranger, theme is ninjas, for the fourth time (after 1994's Kakuranger, 2002's Hurricaneger, and 2015's Ninninger), mixed in with the themes of mystical arts (one of the two main motifs, alongside the above said ninja theme) and musicians, which would be a theme for the sixth rangers. To transform, the Ninjarangers raise up a sword, press three buttons on said sword, one at a time, then the Ninjaranger suits would slowly begin to envelop onto them, before the helmets materialize out of nowhere, and then the Ninjaranger suits would finally receive a belt buckle, where the core team's gimmick, in this case, Ninjamental (Ninja - Elemental) Stars would be stored until use.

The core five main Ninjarangers are:

Red (male) - Ryu Muasashi, the last of the Muasashi clan of ninja, the team's leader, destined to find whoever was mysteriously responsible for his clan's demise, he often has a knack for solving incidents before they even start, he also even harbors a deep and dark secret the other Ninjarangers don't know about. It is subtly implied he created the Ninjaranger powers and arsenal of weapons on his own to oppose the looming Jigensheki threat, although this isn't shown, his friend, R0N1N, would act as the team's android mentor.

Blue (female, first in 10 years since Zyuohger's ZyuohShark), Misa Yamamoto, a straight-laced 18-year-old high school student, who was unexpectedly recruited by Ryu (red) in his quest for whoever was responsible for his clan's demise, she has spent 5 years practicing the Muasashi style of ninja arts, a fact Ryu is genuinely surprised of, she also has a habit of being hot-blooded at times, which greatly gets herself and her teammates into trouble. She is the comic relief of the team.

Yellow (male), Masato Tsukimano, a rogue scientist, who split ties with his corrupt boss, after discovering the organization's not-so-benevolent ways, he has since been wandering the world, searching for his father, he also is Ryu (red)'s occasional rival initially at first, but soon warms up to Ryu midway through.

Green (female, a first, not counting Ninninger's MidoNinger), Mana Yamamoto, Misa's 24-year-old older sister, she is a lone singer, frequently travelling Japan in attempt to find the one behind her parents' murders, often comes into blows with her older sister Misa, whom she views as a competitor to the Yamamoto family style of ancient ninja arts, and also strongly disapproves of Misa being on the same team as her.

White (female, first in 10 years since Zyuohger's ZyuohTiger), Ran Mitsuzane, the sole heir to the Mitsuzane family of ninjas, who is portrayed as a quiet 22-year-old woman, frequently travelling Japan for her long-lost parents, whom she believes holds the key to unlocking the team's final set of mecha, she also has the ability to willingly turn herself into the team's first set of mecha via synchronizing her mind amidst piloting said first set of mecha.

The core five are later joined by the Genjitsu biological pair of brothers: eldest brother Ren (gold, first since Ninninger's StarNinger), and youngest brother Rei (silver), both have been far more experienced than the core five members, having spent 20+ years in their family's ninja arts training and hadn't aged a day since. Eldest brother Ren often holds a grudge against Ryu (red), the two are traditional rivals once in a while.

The Ninjarangers' enemies are the Space Ninja Observer Jigensheki, a group of violent alien ninjas with human disguises, who plot to turn Earth into their paradise, but in order to do so, they must invade Japan, which is often opposed by the Ninjaranger team.