Danno Jo is the Chief Operating Officer (COO) of Tagruato. He is the cousin of Ganu Yoshida and his "right hand man".
Biography
Danno Jo was involved overseeing the development of "vehicles and machinery that will operate at the same capacity as the bulldozers and cranes you pass on the freeway each day, but also function at the ocean's greatest depths."
He was also probably Ganu's cousin referenced in the history page of the slusho.jp website, who took over Noriko Yoshida's drink business after she died and Ganu became an ocean scientist.