Submarine 707R - S01

To maintain peace across the oceans, the PKN was formed, uniting the most advanced battleships from various nations. However, during its founding ceremony, the mysterious organization USR-bent on world domination-launched a surprise attack. The PKN was no match for the submarine UX, commanded by USR's Admiral Red. Just when all seemed lost, the aging Japanese submarine 707, captained by Hayami risking his life, came to their rescue. A year later, the 707 II-a newly built submarine replacing the original, destroyed in battle-set sail with a fresh crew, including former trainees like Kenji, Goro, and Senta. The PKN assembled a fleet led by the cutting-edge American battleship, the Great Guardian, but it was swiftly overwhelmed by the relentless assaults of Submarine U. The 707 II arrived just in time, reigniting Red's rivalry with Captain Hayami as the two engaged in battle. Forced to retreat, the 707 II hid in a valley, but Red attempted to bury it under a mudslide by destroying the surrounding terrain. Narrowly escaping, the submarine became trapped in a crater filled with pure water, leaving it unable to surface. As if things couldn’t get worse, a barrage of torpedoes closed in on the helpless 707.