While undergoing repairs from the fifth war patrol word was received by radio that Germany has surrendered to the allied forces in Europe. The war in Europe ended after five years, eight months and six days, with German representative Col. Gen. Alfred Jodl surrendering in a schoolhouse at Reims, France, at 2:41 a.m. on May 7th, 1945. "With this signature," Jodl said in a soft-spoken voice, "the German people and armed forces are for better or worse delivered into the victor's hand." The following day, May 8th was declared the official Victory in Europe Day, or V-E Day, by the Allies. The United States and Great Britain simultaneously broadcasted the unconditional surrender of Germany at 9 a.m. on May 8.Across the Pacific, a very different celebration commenced nine hours before the official V-E celebration began. Every shore and ship battery trained on a Japanese target fired one shell simultaneously at midnight. The crew of the Parche contributed to the many celebrations that were occurring all over the island. 

Parche then got underway on her sixth war patrol, the last of World War II, on 25 May 1945. after voyage repairs at Guam, she joined the "Lifeguard League" south of Honshu. She stayed on station off Honshu until 18 June 1945, standing ready to pick up any aviators who might be forced down. No rescues were necessary in her area, though, and on the 18th she was released and proceeded to Tsugara Strait, relieving the Pirania.

Parche's first torpedo contact came on 21 June 1945. After hours of watching dozens of patrol craft chug busily in and out, back and forth, a full fledged gunboat was sighted rounding Shiriya Saki. Battle Stations! While the captain was drawing a bead he paused for a look around and remarked rather nonchalantly that we might as well shift targets. Through the fog a freighter, the HIZEN MARU came into the grasp of Parche's torpedoes. Parche got off four torpedoes from her forward tubes for one hit, which threw up a veil of dense white smoke forming the memorial marker for the Jap freighter. Expecting counter-measures, the sub went under, accompanied by the breaking up noises of the freighter. No depth charges were dropped, apparently  the Japs went on to pick up survivors instead of searching for the culprit. Parche continued on her patrol across the entrance to Tsugara Strait.

A slight change of scene to the northward. Dawn on June 22, 1945 found Parche patrolling another promising point. Visibility was next to nothing, and the first few hours of periscope watching produced nothing but a grave doubt as to where in the hell they were and the sighting of a few more Jap small fry hugging the beach. Then at about ten o'clock the fog lifted momentarily, and there was a coastal freighter easing down the line  Back home at battle stations, Parche commenced the approach, one slight handicap becoming apparent in the fact that the target disappeared. Then - there he was, but headed the other way! Shift the rudder, all ahead standard. Another peak, and there was the perfidious Nip again on a reverse course. Shift the rudder, all ahead standard. Then they were all hidden from sight. But JP, good old JP, had screws all around the clock, with bearings changing a mile a minute in all directions. By this time both freighters (and it finally developed that the twins must have crossed ahead of us) were both past, and we were squarely in the middle of a fleet of luggers (small coastal cargo vessels) - this all 5,000 yards off the beach!

Several trawlers were her next target on 23 June. Six five-inch hits sank the first, and eight hits disposed of the second. The third took seven rounds before flooding to the gunwales. 

June 24th was designated as a day of rest yet found themselves cruising once again in the pea soup fog. Parche suddenly picked up a RADAR contact and commenced tracking the target. After two hours of plotting Parche closed for the attack and dove at first sight which was described as the "biggest thing we had seen for a long time." On he came ever closer as only a dark blob in the haze while the torpedo solution was completed. The captain raised the scope for a final observation and bearing when he gasped and collapsed on the conning tower deck beating his fists against the SJ RADAR and kicking the JK. "It's a hospital ship!" moaned the Captain. The toughest situation to bear on one's shoulders and that Jap will never know just how close he came to death.

No doubt, what "Lisbon Earthquake Day" was to the one-hoss shay, June 26th came close to being to the Parche. The day dawned like any other day but it was the one the Parche had waited six runs to see. At about 0900 smoke was sighted to the south close along the coast. Battle stations was sounded and after a long wait  they hove into view. Instead of one, it was three. Instead of three it was five. Instead of five it was eight. Jackpot! Three large ships in column - roughly 3,000, 4,000, and 8,000 tons respectively, with five escorts in a rung. One of the smartest convoys seen in months in Japanese home waters, "all pinging and working as if they had been briefed by the Emperor himself."

But the Emperor’s best were not good enough to play in the same league with the Parche veterans. Serenely sailing under the two leading sub-chasers Parche set herself up into a firing position. Parche's crew fired three torpedoes at the second ship in the column, followed by three more at the third. With stopwatch in hand they waited. Hot, straight, and normal! Two hits accompanied by breaking up noises, were heard on the first target, and two hits registered in the second, whose screws then stopped. Shortly there after the avalanche descended. Depth charges! Cork flew off the bulkheads, light bulbs were bursting, Brown thought he had a gusher in the galley sink. The escorts shook the sub up considerably for four and a half hours, until she finally managed to work away late in the afternoon. As darkness settled down, the most peace loving boat in the pacific fleet boiled out to sea, leaving one ship sunk and another badly damaged.

Three more ships blundered into Parche's lair and were left flooded. During the night of 4-5 July two more anti-submarine craft were sighted, and, suspecting a sweep in advance of a convoy, the Parche fell in behind. Sure enough, before dawn two large ships were sighted, headed for Shiriya Saki through patches of heavy fog. As she closed for a submerged attack, a noisy shaft and reduction gear forced her to break off. On July 8th Parche sank a floating mine by gunfire. On July 16th unknown to the Parche crew the first atomic bomb (16.8 kiloton) is exploded at the Trinity Atomic Test Site in Los Alamos, New Mexico. J. Robert Oppenheimer, the inventor of the atomic bomb was noted as saying, "Now I am become Death, the destroyer of worlds".

Another round of life guard duty for the carrier planes of Task Force 38 was assigned the Parche until 17 July 1945, when she rendezvoused with the Cero to take aboard three fliers, and set course for Midway, arriving on the 23rd. From here Parche proceeded to Pearl Harbor, where she moored on 28 July 1945. The Commanding Officer was awarded the Legion of Merit for this patrol.

On August 6th, the 20 kiloton atomic bomb named "Little Boy" is dropped from the Enola Gay and explodes over Hiroshima, Japan killing 80,000. On August 9th the 22 kiloton atomic bomb named "Fat Man is dropped from a B-29 flown by Maj. Charles Sweeney and explodes over Nagasaki, Japan killing 70,000. Emperor Hirohito and Japanese Prime Minister Suzuki then decide to seek an immediate peace with the Allies. On August 14th, the Japanese accept unconditional surrender, and Gen. Douglas MacArthur is appointed to head the occupation forces in Japan. This day was officially declared Victory in Japan Day or V-J Day by the US Government.