There are multiple artists with this name.
1) SiS is a B-Pop girgroup.
2) SIS is Burak Sar, a techno/house artist.
3) Sis is a Bulgarian R&B/soul singer.
4) Sis is a Turkish hip-hop act.
5) Sis is a Turkish rock act.
6) Sis is a Japanese industrial/psychedelic rock act. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.