252 Signal of Life (Japanese Movie)

Description: A few weeks after a gigantic earthquake struck Tokyo. Metropolitan Tokyo is slowly beginning to function again. But the temperature of the Pacific Ocean suddenly increases after the earthquake, causing a tremendous typhoon. The largest typhoon ever in Japan heads towards Tokyo with devastating force. The tidal wave generated by the typhoon covers the coastal city area with water. The Tokyo Fire Department dispatches its elite rescue unit, Hyper Rescue, and their sonar picks up a signal from underwater. Beneath the ground, in one devastated subway station, there is someone sending out a code which is known to rescuers only?