The chain: Hiriluk → Kureha → Chopper (master inherits from apprentice’s mentor; apprentice inherits from master-of-apprentice’s-mentor). Three generations of Drum doctors converge at the cannon-line:
Hiriluk: the originating dreamer who couldn’t survive to deliver
Kureha: the technical-doctor who finishes the project posthumously
Chopper: the apprentice who witnesses the inheritance and carries the doctrine into the wider world
The structural canonization is a master-apprentice inversion: the master (Kureha) inherits from the apprentice’s mentor (Hiriluk). This is the inverse of the standard apprentice-inherits-master recruitment grammar. Forward-canon: any later Kureha re-appearance carries the inheritor-not-originator register; any later Chopper articulation of the cherry-blossom-bloom-doctrine re-keys this chain.