Hisoutensoku was an unknown huge object witnessed to be roaming around the Misty Lake. It is spotted by numbers of characters before it mysteriously vanishes. In the fact, the identity of Hisoutensoku is the ad-balloon produced by the Kappa to make people know that a bazzar named "Future Water Youkai Bazzar" (mirai suiyou bazâ, 未来水妖バザー) is going to take place, provided by many kappa.