OtomoNin Surfermaru

"Dare ja, dare ja?! Da~re, dare ja?! Dare ja, dare ja?! Da~re, dare ja?! Surfermaru!"

- Summoning announcment

OtomoNin Surfermaru (オトモ忍サーファーマル) is a surfer/submarine based mecha that first appeared in Shinobi 17 of Shuriken Sentai Ninninger. Its default mode is a shark themed submarine and its Humanoid Mode is based off of a surfer.

Overview
The third auxiliary OtomoNin to be created and summoned, Surfermaru would made its appearance from a vortex on the ocean's surface. Like normal submarines, Surfermaru uses its headlights in order to view underneath the ocean, capable of diving and attacking the opponents from beneath with explosive torpedoes. The giant OtomoNin Shuriken: Surfer was placed on the back, which was used as the submarine's turbine.

History
Surfermaru was among the OtomoNin created by Yoshitaka Igasaki, based on the blueprints of OtomoNin UFOmaru.

After Kinji renewed his fighting spirit in defeating Youkai Umibozu, a Sealing Shuriken transformed into OtomoNin Shuriken: Surfer, thus unlocking Surfermaru. Surfermaru was first summoned by AkaNinger, easily evading Umibozu's attacks and transforming into its humanoid form. StarNinger joined and named the OtomoNin, as he entered the Shurikenjin cockpit after Surfermaru combined with it Shurikenjin Surfer to destroy Umibozu. After StarNinger's deadline of defeating the Ninningers had passed, Surfermaru was given as a parting gift to him as he used it to get back to America.

While Kinji was vacationing in Hawaii with Surfermaru, Takaharu forgot to give the Surfermaru Nin Shuriken to him when he left. When the team needed Surfermaru and Takaharu realized this, he summoned the OtomoNin to help as both UFO Maru and Shurikenjin Drago were disabled. This also caused Kinji to be brought into the fight unintentionally, as he was still inside Surfermaru enjoying lunch when they summoned it. Using Shurikenjin Surfermaru, they defeated Otoroshi and convinced Kinji to stay in Japan.

Even with Surfermaru now as Kinji's personal OtomoNin, like all auxiliary OtomoNins, Surfermaru would later be deployed whenever its Nin Shuriken in use.

Humanoid Form
Once the "OtomoNin Transformation" (オトモ忍・変形) is announced, half of Surfermaru transforms into a humanoid form while the other half transforms into a surfboard and the giant OtomoNin Shuriken: Surfer is removed. The mecha is capable of manipulating tidal waves to increase its advantage in surfing on the ocean.

Shurikenjin Surfer
"Surfin'! Wasshoi! Surfin'! Wasshoi! Shurikenjin Surfer! (Guitar solo beach fanfare)"

- Shurikenjin Surfer combination announcement

Shurikenjin Surfer (シュリケンジンサーファー) is an alternate form of Shurikenjin formed when Surfermaru takes over Shinobimaru's place with the OtomoNin placed into the formation's right hand, while the giant OtomoNin Shuriken: Surfer is placed on the head in place of the Shinobimaru one. This is performed when AkaNinger spins his OtomoNin Shuriken: Surfer in the Ninja Ichibantou and the "Shuriken Surfer Combination" (シュリケンサーファー合体) is announced.

In this formation, Shurikenjin retains the Drago Sword (ドラゴソード) as a side weapon while given a surf board that Surfermaru rides. The mecha is capable of manipulating tidal waves to increase its advantage in surfing on the ocean. The surfboard is also capable of acting as a skateboard when battling on land.

Its finisher attack is Shurikenjin: Surfer Surfing Slash (シュリケンジン・サーファー波乗り斬り), where Shurikenjin Surfer surfs into the enemy and slashing it with Drago Sword.

BisonKing Surfer
BisonKing Surfer (バイソンキングサーファー)