Yokai Kappa

"Pretty tough! See ya later!"

- Yokai Kappa before taking flight and then firing on Shurikenjin as well as his final words before his death.

Yokai Kappa (voiced by Hironori Kondō) is the second Yokai the Ninningers fought, having spawned when a Sealing Shuriken attached itself to a fire extinguisher. He is also known as River Monster Kappa during his introductory shot.

History
Kappa was detected by the Gama Gama Guns terrorizing a lakeside community with some Hitokarage until the Ninningers interfered, with AkaNinger fighting Kappa in a spot conveniently shaped like a sumo ring, which ended when Kappa flung AkaNinger to the water, but like any ninja, landed on the water's surface, and began running back. Defeating AkaNinger with his foam attack, he then dispatches all but AoNinger, who had been observing the battle while this was going on, who using the fire setting on the Goton Nin Shuriken to constantly bathe Kappa in flame when he tried going for KiNinger until the Yokai couldn't stand the flames and jumped into the lake, jumping rudely on KiNinger while doing so.

When Kappa returned to cause some havoc, he happened to be near Yakumo, who quickly transformed and began attacking Kappa, though it ended in the Ninninger's defeat when the two tried an elemental clash only for Kappa to reveal an ace up his sleeve. When he tried to freeze a downed Yakumo, Takaharu jumped in for the rescue, using a perfect Kaen Jutsu against Kappa.

Once regrouped and transformed, the Ninningers began attacking the Kibaoni forces with full fervor, with AkaNinger and AoNinger double-teaming the Yokai with their Goton Nin Shuriken, cracking Kappa's helmet. With that, Kappa was felled by AkaNinger and AoNinger's Ninja Violent Slash.

Once revived by Kyuemon, the Ninningers formed Shurikenjin to combat the enlarged Kappa. After getting smacked around, Kappa decided to show that the nozzles trailing from his body were not for show, and began to fly off. In response, Takaharu rushed out on Shinobimaru to try to get him out of the air, only to realize Shinobimaru's jumps aren't as excellent as he thought, and was seized by Kappa.

With a hint of exasperation, Yakumo disengaged from the combination, with Dragomaru freeing Shinobimaru with a burst of flame, the Otomonin landing on Dragomaru's back. Before Takaharu can restart the combination, Yakumo spun his Otomo Nin Shuriken to form Shurikenjin Drago, giving the Ninningers the even ground they needed, eventually grounding Kappa, resulting in his destruction when Shurikenjin Drago fired the Drago Burst and the purification of the Sealing Shuriken that spawned him.

Kappa was among the mentioned Yokai the Igasaki Ninningers noted to Kinji Takigawa they had destroyed prior to his arrival, making him displeased that he didn't have the chance to defeat them personally as StarNinger.

Kappa was part of a group of 100 revived Yokai that appeared on the day of Hyakki Yakou and were fought by AkaNinger and StarNinger. During the contest between the two Ninningers to defeat the most Yokai, Kappa was destroyed alongside Tsuchigumo by AkaNinger and StarNinger's Ninja Violent Slash and Lightning Rockstar.

Trivia

 * The elements of Yokai Kappa's costume were later reused to create the Advanced Yokai Oumukade.