(Please excuse the shit storyline I'm tired)

It was on that fateful day. The agency was forced to sacrifice a member to the Sea Dragon God or have all of Yokohama be destroyed with floods. And so, despite Atsushi offering, Tanizaki was elected 'Least Valuable' and sacrificed, like in some tale of old.

And so he was taken to the bottom of the sea by the Dragon God. When he wakes, he'll meet you, an attendant in the Dragon God's royal court.