Super Sentai Chapter 26: Ninpuu Sentai Hurricaneger

Ninpū Sentai Hurricaneger ("Stealth Wind Squadron Hurricaneger") is the twenty-sixth installment in the Super Sentai series, airing from 2002 to 2003.

Upon the graduation day of Hayate Way Ninja Academy, an alien ninja clan called the Jakanja descend on the school and kill the entire student body. The only survivors are three students who happened to be elsewhere doing remedial training.
Out of desperation, the three students are given the school's greatest honour so they can fight against the Jakanja: the power to become Hurricanger.

Our Heroes are The greatest warriors of Hayate Ninja Academy. Uh, by default. To cover up their ninja identity, they blend in the society taking up normal jobs.

.Yōsuke Shina / Air Ninja, Hurricane Red: idiot Hero, Determinator. Uses the guise of a cleaning worker when not doing ninja stuffs.

.Nanami Nono / Water Ninja, Hurricane Blue: The Chick. Her 'spare time' guise is an Idol Singer.

.Kōta Bitō / Land Ninja, Hurricane Yellow: Big Smart Guy. When not doing ninja things, he works in a daycare center, taking care of mostly the elderly.

There is also Denkosekka Gouraiger: A rival team to the Hurricanger. The Gouraiger are two brothers who are the only survivors of Ikazuchi Ninja Academy, a rival school to Hayate. Both disguise themselves as construction workers.

They are:

.Ikkō Kasumi / Horned Ninja, Kabuto Raiger: The Number 2

.Isshu Kasumi / Fanged Ninja, Kuwaga Raiger: The Tagalong kid

The Main Villian is Boss Tau Zanto: The leader of the Jakanja invaders is a centipede-like demon with various faces on his segments who learned of the Evil Force 500 years ago and intends to evoke it to destroy the universe and become a god of the new universe that would be created as a result. From the very start he attempted to bring about the Evil Force's coming by having the Gouraigers kill each other and Fangerus. Though both attempts failed Tau Zanto found an alternate means after probing his henchman, Manmaruba's mind to learn of the Raging Arrow and the Grieving Bow. Once he ingested both weapons Tau Zanto used Satarakura to gather enough energy to assume a suitable form, the gigantic Tau Zanto Ultimate Form. Though he was able to open the wormhole Sandaaru wounded Tau Zanto forcing him to make his way in and become one with the Evil Force. As it began to destroy everything the Hurricanegers managed to reverse the process. Tau Zanto, with the Evil Force inside him, emerged and fought Senpuujin. Tau Zanto, mortally wounded, grabbed Senpuujin as he exploded but Tau Zanto survived and assumed the guise of all Seven Lancers until the two Ranger teams defeated them. Tau Zanto proceeded to overpower the Rangers without mercy but their refusal to give up enabled them to kill Tau Zanto with the Victory Gadget destroying the Evil Force forever.

Horrific this episode should never have aired on TV.

Your writting was quite accurate but the premise-YKES