They were the former hosts for the Inkopolis News program, which announces events, new DLC and other battle-related news. They used to host and manage Splatfests. Their voice actors are Keity. In the Super Smash Bros series, they appear as an assist trophy. They will cause the screen to zoom towards them while singing either Ink Me Up or Calamari Inkantation. Not only that, but the Squid Sisters are a legendary support spirit in said game, which causes the player's Final Smash Meter charges more quickly.
Squid Sisters Stories
Callie - Inkipedia, the Splatoon wiki
Together, they host Inkopolis News , announcing events, updates , and the current stages in rotation. They also host Splatfest events, with each Sister representing one of the two teams. Despite their name, they are actually cousins, not sisters. For solo songs, see Callie and Marie. Callie's color scheme is magenta and black. She has an edgier design in comparison to her cousin, with angular eyes and perked-up ears.
Callie is a part of the Squid Sisters pop idol duo and a former host of Inkopolis News , along with her cousin Marie. Her signature color is magenta. Callie is a very fashionable Inkling and has a more 'edgy' design in comparison to her cousin. Her tentacles, which are black with a purplish-pink tinge at the ends, are very long and tied in a large bow on the back of her head, leaving the ends to dangle, along with a bang swept to the right of her face. She has large, angular eyes with gold irises and light-brown pupils in the shape of a plus.
They are Inklings , but unlike most Inklings, they have two main hair colors. Despite being called the "Squid Sisters", they are actually cousins. In the original Splatoon , Callie and Marie are a pair of pop idols who host Inkopolis News , where they announce what stages are available for online multiplayer as well as giving information on updates and Splatfests. During Splatfests, Callie and Marie can be seen in Inkopolis Plaza performing atop trucks, much like their Assist Trophy function, although each Squid Sister has their own truck rather than performing on the same stage, due to each of them backing one of the Splatfest teams. These concerts can also be viewed through the use of amiibo.