In MakoMart, there are cereals with Pearl and Marina's logo on it, possibly being Off the Hook branded cereal. It is shown topping Crusty Sean's Galactic Shwaffle. [9] On February 10, 2018, the Squid Sisters made a special appearance at "Haikaraibu" (Japanese: ハイカライブ, translating to "Inkopolis Live"), which was held at Tokaigi 2018. [6] After Off the Hook performed Ebb & Flow, Callie and Marie went on stage to perform Fresh Start, followed by Spicy Calamari Inkantation. Afterwards, both the Squid Sisters and Off the Hook performed Now or Never! as the finale. When Cap'n Cuttlefish is kidnapped in Octo Valley, replaying previous missions also has his dialogue missing.

On 10 February 2018, the Squid Sisters made a special appearance at " Haicalive" (Japanese: ハイカライブ, translating to "Inkopolis Live"), which was held at Tokaigi 2018. [8] After Off the Hook performed Ebb & Flow, Callie and Marie went on stage to perform Fresh Start, followed by Spicy Calamari Inkantation. Afterwards, both the Squid Sisters and Off the Hook performed Now or Never! as the finale. An English version of this concert was held at Polymanga in Montreux, Switzerland before the final rounds of the Splatoon European Championships on 31 March 2018. On 28 April 2018, another Haicalive concert was held at Cho-Ongakusai 2018. [9] Their setlist was the same as the previous recent concerts, but their dialogue in between songs was different. A recording of the first Haicalive concert was included on Octotune, as well as a limited edition Blu-ray, which both released on 18 July 2018. Marie stayed at Cuttlefish Cabin to look after Octavio while waiting for Cuttlefish to return, where she was later joined by Callie. They provided various stats and information about the player during their conversations with Agent 4. Callie: "Sigh... This Splatfest is going to be trouble." Marie: "And make it double!" Callie: "We'll protect Inkopolis from devastation!" Marie: "And unite all squids within our nation!" Marie also made a major appearance during Octo Valley. After initially making a news broadcast about the disappearance of the Great Zapfish, she appeared as Agent 2 of the New Squidbeak Splatoon, led by her grandfather, Cap'n Cuttlefish, with Callie as Agent 1. Throughout Octo Valley, Marie was heard communicating to Cuttlefish, Callie, and Agent 3 regarding the looming Octarian menace. Once Cuttlefish was kidnapped after Agent 3 defeated the Octomaw, the two agents acted as Agent 3's mentors in his place, albeit in disguise, not revealing their true identities. Using the Squid Sisters' amiibo applies all the cosmetic changes of a Splatfest to Inkopolis Plaza, and the player can choose what song they perform. This is the only way to see the accompanying dances for these songs, with the exception of City of Color, the default for Splatfests.

Cap'n Cuttlefish's Theme• Octo Valley• Eight-Legged Advance• Tentacular Circus• Cephaloparade• Inkstrike Shuffle• Octoling Rendezvous• Octoweaponry• I am Octavio• Calamari Inkantation• Maritime Memory• Onward!• SPLAT!• Sunken Scroll Marie has an appreciation for Agent 3's Smallfry in Splatoon 3, shown in her dialogue throughout the game. She sometimes even seems to forget about Agent 3 in favor of Smallfry. Callie and Marie were from Calamari County, where they were born and raised. After they won Inkopolis' first annual Youth Folk-Singing Contest, they moved to Inkopolis where they began their career as announcers for Splatfests and musicians.

The Squid Sisters are the only idols to have been in a concert with Off the Hook and Deep Cut, with the latter being "special guests" invited by Deep Cut. The Splatoon amiibo figures can be tapped once a day in Hyrule Warriors for a weapon rated three stars or lower, a Rupee bonus, or a crafting material bonus. Most of the other amiibo figures can be used for this as well, however. [5] Hyrule Warriors: Age of Calamity The hand movement they do during their catchphrase, "Staaaay fresh!", is supposed to resemble the moving tentacles of a squid. Holding down on causes all Splatoon costumes to lie down in their squid forms, with the same sound used when turning into a squid in Splatoon. When playing on an underwater level, all costumes swim in their squid form.During her performance of City of Color (2023) in Splatfests, when she does the jumping part of the choreography her hat stays on her head, as opposed to bouncing like it did in Splatoon's Splatfests. Marie appears alongside Callie during the Inkopolis News section, revealing the current stages in rotation, as well as hosting the Splatfests. She also appears as Agent 2 during Hero Mode, where she, along with Callie, guides Agent 3 after their grandfather Cap'n Cuttlefish gets kidnapped by DJ Octavio. She and Callie also sing the Calamari Inkantation during Agent 3's fight, which later proves to be a significant act as this allows many Octarians (or at least Octolings) to break free of DJ Octavio's control, including Marina Ida and Agent 8. When the Smallfry amiibo is scanned in the amiibo box, instead of talking to the player like most amiibo, an unknown narrator helps communicate with the Smallfry. After the events of the first Splatoon's final Splatfest, the Squid Sister's popularity rose to never seen before heights. However, the two cousins pursue their own solo careers, causing a rift between them, and Callie eventually goes missing. After Marie notices that the Great Zapfish and DJ Octavio have both also gone missing, she worries that Callie's disappearance is connected to them. She decides to recruit a new Inkling to the New Squidbeak Splatoon, with them being Agent 4, to help find the Great Zapfish. Eventually, Marie tells Agent 4 that she is also looking for Callie. Marie and Agent 4 eventually find Callie, now brainwashed into serving DJ Octavio. Marie uses a special substance she made called the low-tide ink to free Callie from her brainwashing, and then the two of them, now reunited, sing a remix of the Calamari Inkantation called the Spicy Calamari Inkantation as Agent 4 uses a modified version of the Rainmaker given to them by Sheldon to defeat Octavio, saving the Great Zapfish once more.