He is one of the 12 Directors of Academy City, in charge of all military aspects such as defense and R&D of military technology. He always wear a HsPS-15 Suit, not because he is paranoid about attacks on him but he can't be at ease without it.

In the Light Novels he first appeared in Volume 19, as the antagonist plotting and attacking GROUP.

After his defeat he revealed DRAGON's identity, saying it's something he wished he never knew of its existence, but as the one in charge of defending Academy City against the 'outside' he needed to know. Shiokishi was then knocked out by DRAGON afterwards, and it is unknown whether he is dead or alive after that.