Marvel Database calls him letterer and production artist. He's credited with "creating" many covers, all of them by other artists, many of them signed by other artists but not by Kuramoto. I can't find any samples of his artwork to compare against, but I can identify most, if not all, of the pencilers and inkers' artwork used by Marvel during this period. At most he did touch up art, at least cover paste-up (laying out the art together with cover logo, corner vignette, and captions, things like that).
So can anyone shed some light on why this man is being credited as cover artist on covers other people did? If he did touch-ups, can you tell me which elements are his?
For example, the cover of Avengers 136 is credited to Gil Kane (P), Mike Esposito (I), Romita and Kuramoto. The vignettes of Captain America and Thor are by Romita. Is the Vision vignette Kuramoto's? I can tell it was inked by Esposito.