Asian Mark on Modernist Earrings

[fashion.fashoff]

I have two pairs of handmade sterling earrings c. 1980s. One is marked STERLING with a mark of a superimposed HM or MH. The other is marked similarly with additional marks of © and an Asian (Japanese?) character.

I am hoping somebody can identify the Asian mark so I can try to research the maker.

Pictured below are my two earrings and the marks, in addition to a 3rd pair of earrings by this maker (with a better mark photo) from an online seller.