Sabikui Bisco, Vol. 5 (light novel)

In order to get his full-sized body back and stop the insatiable blossoms from ravaging Hokkaido, Bisco raises hell to track down the mysterious mushroom hidden on the island. But his way is barred by the very person who made him this way: the ruler of the Benibishi-Shishi. And if that wasn't enough, a mysterious sea monster joins the fray!