|This article is about a/an ally in Samurai Sentai Shinkenger.|
Hikoma Kusakabe (日下部 彦馬) is one of Takeru's retainer and his guardian after his father's death.
He also serves as the Shinkengers' mentor; it is he who gathered the four vassals when the Gedoshu revived. The Shinkengers affectionately call him "Jii" (ジイ, translated as "old man"). Every year, he gets one day off, which he uses to visit his wife's grave and visit his daughter, son-in-law, and granddaughter.
His relationship with Takeru and his vassals runs deep; he takes great care to ensure that they are safe and that they are ready to fight, and he supplies them with information and weaponry. Though Genta frequently annoys him, Hikoma acknowledges the younger man's skill with Mojikara and eventually does accept and connect with him.
Like Mako, he is adept at reading people and often helps the vassals with their personal problems. He doesn't get horse riding since he has trouble with his lumbago, but he rides on his motorcycle instead. He is very good at the performance of an electric guitar. When he goes to a hospital to be treated for a hip injury, he happens upon the Hikari Studio and gives invaluable advice to Tsukasa Kadoya during the meeting of the worlds of Kamen Rider Decade and Samurai Sentai Shinkenger.
While Hikoma does not typically take up arms himself, his "battle" is to ensure that Takeru and his vassals remain safe and will always have someplace to which they can return. When Kaoru makes her appearance, Hikoma remains loyal to Takeru, but bears no ill will towards Kaoru; he respects her for both her title and for the kind and diligent young woman that she is.
After the final battle, he stays with Takeru even when he insists that he go visit his family and encourages Takeru to join him to experience other lifestyles other than just the samurai life, like learning to speak English or play guitar.