The year was 1958 and Varan's assault on Haneda Airport was in full swing. Because no weapon could pierce his immense hide, the government was desperate and decided to use a special type of dam explosive to blow Varan up from the inside. The P2V-7 Neptune would be the carrier of such a weapon. When the craft was above Varan, the flickering explosives were released, attracting the creature's attention. Varan ate the glowing objects, unaware of their true purpose. One of the devices detonated, weakening him severely and forcing him to retreat into the ocean. When he thought he had reached safe haven in the sea, the second exploded. The monster's rampage was ended.

When the year 1964 rolled along, the P2V-7 Neptune would be used yet again as the space monster Dogora attacked Japan. It's weakness to bee and wasp venom was discovered and the SDF intended to use this knowledge to their advantage. The P2V-7 Neptune would be one of the vehicles that would carry this payload into battle against Dogora. By releasing an artificial venom in the form of gas, Dogora's cells began to crystallize until the creature was no more. The P2V-7 Neptune is, to date, one of the few SDF weapons to boast a perfect survival record in the face of invading monsters.