Muramoto, or more precisely Master Muramoto, is a Japanese ninja master, destined to train Spider-Man's part-time villain/friend Puma to take on the Beyonder, an all-powerful godlike entity that is the personification of a pocket universe that came to sentience when the villain Molecule Man gained his superpowers and the energies thereof pierced a hole in said universe making the Beyonder aware of...phew!
Anyway, this almost ancient ninja sensei converted to the Beyonder`s case, joined the Beyonder-inspired sect Cosmic Oneness and started his own (unnamed) punk rock band, with himself on lead guitar and vocals.
His first, and to date only, appearance as a punk rocker was in Spectacular Spider-Man vol. II # 111.
Of interesting note, his/their first gig was at a nightclub owned by "Ralph Macchio," the name of the Marvel Comics editor-in-chief at the time.