Yakumo Yukari

"I...have arrived (at last/once again)!"

is one of the main good Imagin in the series Eastern Land Series, he allows him to use Den-O's Sword Form. Momotaros eventually becomes the representative of the Eastern Land series, becoming Kamen Rider Den-O (仮面ライダー電王 Kamen Raidā Den'ō, lit. "Power King") himself.