Antifreeze protein (AFP) initially isolated from blood serum of polar fish in 1960's is an extraordinary bio-molecule that specifically binds to the surface of an ice crystal to inhibit its growth below 0oC, and also to the membrane surface of a cell to improve its viability above 0oC. We discovered for the first time that approximately 50 kinds of Japanese edible fish also contain AFP, and developed an easy method to obtain ~kg order of natural AFPs from the fish muscle. We also found that an AFP isoform having no antifreeze activity exhibits an extreme cell-preservation ability. Based on the knowledge of biochemical/biophysical properties and structure-function relationships of our original AFPs, the AFP-team is trying to develop new AFP-technologies applicable from industry to medical fields.