King of Pro-Wrestling featured professional wrestling matches that involve different wrestlers from pre-existing scripted feuds and storylines. Wrestlers portray villains, heroes, or less distinguishable characters in the scripted events that build tension and culminate in a wrestling match or series of matches.
King of Pro-Wrestling was main evented by Kazuchika Okada defending the IWGP Heavyweight Championship against SANADA. On March 24, 2019, Okada defeated SANADA in the finals to win the 2019 New Japan Cup and earn the right to face Jay White at the main event of the G1 Supercard on April 6. After winning the tournament, Okada promised that after he won the IWGP Heavyweight Championship he would give SANADA a rematch. At the event on April 6, Okada defeated White to win the IWGP Heavyweight Championship for the fifth time. On May 4 at Wrestling Dontaku, Okada successfully defended the IWGP Heavyweight Championship against SANADA. Later that year, Okada and SANADA took part in the 2019 G1 Climax, with both wrestling in block A. Despite neither of them managed to advance into the finals, SANADA defeated Okada in their head-to-head match. On August 31 at Royal Quest, after Okada successfully defended the IWGP Heavyweight Championship against Minoru Suzuki, SANADA challenged Okada to a match for his title, which he accepted. The title match was announced on September 2.
In the IWGP Junior Heavyweight Championship match, Will Ospreay who made his second title defense against the winner of the 2019 Super J-Cup El Phantasmo. On May 4, 2019, at Wrestling Dontaku, El Phantasmo made his debut in NJPW, teaming with his Bullet Club stablemate Taiji Ishimori in a winning effort against Dragon Lee and Will Ospreay, after Phantasmo pinned Ospreay. Later that month, Phatasmo and Ospreay took part in the 2019 Best of the Super Juniors, wrestling in block B, in which Phantasmo defeated Ospreay in their head-to-head match. In June, Phantasmo started feuding with Ospreay, after Robbie Eagles turned on Phantasmo to join CHAOS. In August, Phantasmo and Ospreay took part in the 2019 Super J-Cup, where in the semifinals of the tournament, Phantasmo defeated Ospreay, with the help of Taiji Ishimori to advanced into the finals. After Phantasmo won the Super J-Cup on August 26, Phantasmo challenged Ospreay to a match. On August 31 at Royal Quest, after Phantasmo and Ishimori lost to Ospreay and Robbie Eagles, Phatasmo challenged Ospreay again to a match for the IWGP Junior Heavyweight Championship. The title match was announced on September 2.
In the IWGP United States Heavyweight Championship match, Jon Moxley was supposed to make his first title defense against Juice Robinson. In April, NJPW began airing pre-taped vignettes of a mystery man targeting Juice Robinson, which was later revealed to be Jon Moxley. Moxley would make his debut in NJPW on June 5, defeating Juice Robinson to win the IWGP United States Heavyweight Championship. Afterwards, Robinson undergone a long period of self reflection. In August, Moxley and Robinson took part in the 2019 G1 Climax, with both wrestling in block B. In their head-to-head match, Robinson managed to defeat Moxley, costing him a place in the finals of the tournament. On August 12, Robinson and Toa Henare faced Moxley and Shota Umino in winning effort. After the match, Moxley attacked Robinson and put him through a table. Afterwards, in a post-match interview, Moxley offered Robinson a rematch for the IWGP United States Heavyweight Championship, if it was a no disqualification match. Robinson accepted the Moxley's challenge on August 31 at Royal Quest. The title match was announced on September 2. On October 14, Moxley would miss the event due travel delays due to Typhoon Hagibis, and as a result the title has been declared vacant and a match between Robinson and Lance Archer for the title would be taking place.
In the Tokyo Dome IWGP Heavyweight Championship challenge rights certificate match, Kota Ibushi who made his second defense of his contract against EVIL in a rematch from 2019 G1 Climax. On August 13, Kota Ibushi defeated Jay White in the finals to win the 2019 G1 Climax. Following the win, Ibushi gained possession of a contract for an IWGP Heavyweight Championship match at NJPW's biggest event of the year, Wrestle Kingdom 14 in Tokyo Dome on January 4, 2020. After making his first defense of the contract against KENTA on September 22 at Destruction in Kobe, EVIL challenged Ibushi to a match for his contract. The title match was announced on September 24. Ibushi and EVIL had previously faced each other during the 2019 G1 Climax, which EVIL won after taking advantage of Ibushi's injured ankle.
The event included a singles match between Jushin Thunder Liger against Minoru Suzuki. In April 2019, Suzuki began attacking Liger after their matches, with Suzuki remembering Liger of their MMA match at Pancrase in 2002, leading Liger to challenge Suzuki to a match under professional wrestling rules, rather than a fight which Suzuki demanded. In September, during the Road to Destruction tour, Suzuki reignited his issues with Liger and began attacking him again, leading Liger to grow further incensed with Suzuki and declaring that he had "no place in a NJPW ring". During the tour, Suzuki tried to forcibly remove his Liger's mask, declaring it represented the long since departed soul of Liger, but Liger warned Suzuki to stop. On September 22 at Destruction in Kobe, during a six man tag team match, Liger voluntarily unmasked himself to reveal his alter ego "Kishin Liger" and afterwards started to attack Suzuki, leading him to retreat, in which Liger pursue him in to the back, which led to man officials and young lions try to separate him. The match was announced on September 24. The last time Kishin Liger appeared was on June 16, 2012, at Dominion 6.16, during a match, where Liger teamed with Tiger Mask against Suzuki's Suzuki-gun stablemates Taichi and Taka Michinoku for the vacant IWGP Junior Heavyweight Tag Team Championship. The change was brought on by Taichi tearing Liger's mask to pieces.