With a strong wrestling pedigree as a fourth generation wrestler, David made his NJPW debut during the 2015 Best of the Super Jr. tournament, and entered the New Japan Dojo soon after. David Finlay’s NJPW journey would be defined by connections he made in that time; Jay White would become a rival he would be desperate to beat, while Juice Robinson would become a key ally with whom he won the 2019 World Tag League, and took the IWGP Tag Team Championships at Wrestle Kingdom 14. 

FinJuice would also win IMPACT tag gold in 2021 before Juice Robinson disbanded the team, joining BULLET CLUB shortly afterward. Angered at being looked past and left behind, Finlay would join his first G1 Climax in 2022 with a chip on his shoulder, and picked up huge wins over Shingo Takagi, Will Ospreay and his former partner Juice. 

At Battle in the Valley 2023, Finlay attacked the departing Jay White after he lost a loser leaves NJPW match. Taking charge as the new BULLET CLUB leader, the Rebel stated that from now on the group was for ‘savages only’; squashing dissent, he expelled El Phantasmo and enlisted Clark Connors, before challenging for the NEVER Openweight Championship. Finlay won in brutal form over Tama Tonga, but his past would come to kick him in the face, as Phantasmo returned and confronted his former teammate. At Dominion6.4 in OSAKA-JO HALL, Finlay savagely hurt Phantasmo in the NEVER Openweight Championship match,  successfully retaining the title.