In 1999, Shigetaka Kurita created 176 emoji as part of NTT DoCoMo's i-mode, used on its mobile platform.[25][26][27] They were intended to help facilitate electronic communication, and to serve as a distinguishing feature from other services.[6]
As in the title of the linked article, the earliest emoji are not from 1999, or 1997, but from 1988. I know, because I'm the guy that discovered them.
But, yes, they're emoji because they were created and named in Japan. The IBM set serves a different purpose and exists in a different context. But, they are both living happily alongside each other in Unicode.
https://en.wikipedia.org/wiki/Code_page_437