I found this entry mentioning Meiju From this site : https://datekatana.jp/en/column/tsuba-artisan-guild-independence-school-formation
During this period, "Umetada Meiju" appeared. While possessing the skills of a sword smith, Meiju elevated the creation of tsuba and sword fittings to an art form, introducing "pictorial high relief carving (takabori) and inlay work (zougan)" to tsuba—a revolutionary artisan. The appearance of Meiju became the turning point in establishing tsubashi socially as "metalcraft artists."
But I think it merely reflects a misspelling of Myōju.
From Captain F. Brinkley's "Sculpture on Sword-Furniture" [1902] He lists a Meiju, Umetada Okada. 1640 - originally an artist from Kyoto, but moved to Hagi in Choshu and founded the Okada family. I find Brinkley very unreliable.