Seikai

"NinjaYellow! Seikai!"

- NinjaYellow's roll call

Seikai (セイカイ) is NinjaYellow (ニンジャイエロー) of the Kakurangers. He is 24 years old and a descendant of Seikai Miyoshi.

Kakuranger
Seikai first encountered the Youkai when a friend of his was kidnapped by Rokurokubi, who thought he was her deceased son. Seikai fled with his friend and was rescued by Tsuruhime, Sasuke, and Saizou. They brought him to where his ancestor's sword was placed in the Earth. Upon pulling out his sword, the spirit of Seikai's ancestor appeared before him, gave him a lecture, and entrusted him with a Doron Changer, allowing Seikai to become NinjaYellow. The four were soon joined by Jiraiya, completing the team.

Super Sentai World
When Emperor Daidas and his army invaded Earth, Seikai, alongside his team, joined with the four Sentai that came before them, the Dairangers, Zyurangers, Jetmen, and Fivemen, to defeat him.

Ole vs. Kakuranger
to be added

Gaoranger vs. Super Sentai
NinjaYellow is among the Sentai warriors seen in clips when Gouki (GingaBlue) lectured Soutarou Ushigome (GaoBlack) about the past Sentai strong warriors, humbly claiming to not be nearly as strong as they are.

Legend War
Years later, Seikai fought alongside not only his own team, but every single Sentai ranger in existance, against the Empire of Zangyack when it attacked the Earth in the Great Legend War. After fighting against hundreds of Gormin and their Zgormin commanders. Kaijou noticed the fleet moving towards them, he gathered all the Rangers together and gave them the order to sacrifice their powers to wipe out the first invasion's armada. The NinjaYellow powers are later used by Luka Millfy via the Ranger Keys.

Farewell Space Pirates
After the Zangyack's final defeat, Marvelous returned the Ranger keys to their original owners. It is assumed Seikai, Tsuruhime and their teammates have their powers once again and will work alongside Ninjaman to cut down evil in the shadows once more.

Super Hero Taisen
Seikai, alongside his team (bar Ninjaman), among the majority of the Super Sentai heroes, was caught up in the "Super Hero Taisen" incident which eventually resulted in the Super Sentai teams and Kamen Riders joining forces to defeat both Dai-Zangyack and Dai-Shocker.

Super Sentai Battle: Dice-O

 * Profile
 * Seikai/NinjaYellow: to be added

Personality
Seikai likes video games. He is driven by desire for food, sleep, and women. He is indecisive, but has unusual strength inheirited from his ancestor. He corresponds to Zhu Bajie.

Forms
{{#tag:tabber| NinjaYellow=

Sanshinshou
 * Giant Beast General Yellow Kumard
 * Beast General Fighter Battle Kumard
 * Super Stealth Beast God Kumard

Arsenal
 * Doron Changer
 * Secret Sword Kakuremaru
 * Kakulasers / Laser Knives
 * Shinobi Knuckles
 * Yellow Claw
 * Kakuranger Ball
 * Shark Slider

Attacks
 * Hidden Style: Triple Slash
 * Echo Art
 * Leaf Hiding Art

{{!}}-{{!}} Beast General= {{#tag:tabber| Giant= {{nihongo|Giant Beast General Yellow Kumard|巨大獣将イエロークマード|Kyodai Jūshō Ierō Kumādo}}: NinjaYellow's Juushou form, armed with the Kumard Claw, with which he can entangle and grab enemies. It can perform the 'Kakureryuu Ninpo Kaen Rin' (Hidden Style Ninja Magic Flaming Ring), a hoop of fire. Forms Muteki Shogun's right leg. Its name is a pun on the Japanese word for {{nihongo|bear|熊|kuma}}}.

{{!}}-{{!}} Fighter= {{nihongo|Beast General Fighter Battle Kumard|バトルクマード|Batoru Kumādo}}: Ninja Yellow's Juushou Fighter form, armed with the {{nihongo|Kumard Head|クマードヘッド|Kumādo Heddo}}. {{-}} }} {{-}} }}

Ranger Key
The NinjaYellow Ranger Key (ニンジャイエローレンジャーキー) is Seikai's personal Ranger Key and what became of his powers after he along with the rest of the 34 Super Sentai sacrificed their powers to end the Great Legend War.

This key along with the majority of the Ranger Keys were collected by the Red Pirates and later used by the Gokaigers. The NinjaYellow Ranger Key was mainly used by Luka Millfy (Gokai Yellow), who used it to fight as NinjaYellow.
 * When the Gokaigers became the Kakurangers to escape from Action Commander Shieldon.
 * When the Gokaigers became the Kakurangers while fighting against Action Commander Bibabu.
 * When the Gokaigers became the Kakurangers while fighting alongside Ninjaman against Action Commander Juju.

The Kakuranger keys, along with all the Ranger Keys of the first 33 Super Sentai, were briefly taken by the Black Cross King and turned into Ranger puppets that were fought by the Gokaigers and the Goseigers. The Kakuranger keys were defeated by Gokai Green.

After Zangyack were finally defeated, the Gokaigers gave the Ranger Keys back to their rightful owners. It is presumed that Seikai received his key and became NinjaYellow once more.

Portrayal
Seikai is portrayed by Shu Kawai (河合 秀). As NinjaYellow, his suit actor was Hirofumi Ishigaki.