A vocal unit who performed the theme song for KAMEN RIDER × KAMEN RIDER OOO & W feat. SKULL: MOVIE WAR CORE.
Comprised of Maki Ohguro and Koji Kikkawa, who performed songs for KAMEN RIDER OOO and DOUBLE, respectively.

The name is derived from the first kanji of their surnames, '大' for Ohguro and '吉' for Kikkawa.