Third season of Xian Wang de Richang Shenghuo.

After regaining her squid-like abilities, Ika Musume plans to resume her self-appointed mission to destroy all of humanity. However, her carefree job as a waitress in the Lemon beach house meant she cannot help but laze around during her spare time! On top of that, she is saddled with many problems, such as being pursued by a group of alien-obsessed individuals and catching the interest of a crazy girl. Picking up after the conclusion of the first season, Shinryaku!? Ika Musume follows the hilarious life of Ika Musume as she plots her next invasion of the surface world.

After Kanna Kamui's escapade to New York leads her to make a new friend named Chloe, Kanna invites her to Japan to go sightseeing. Following their reunion at the airport, Kanna—accompanied by Kobayashi, Tooru, and other friends—takes Chloe around the attractions of Japan, starting with Akihabara. Expertly guided by Tooru, the group enjoys exploring the city before returning home to meet with Saikawa and continue their adventures. As Chloe's final day in Japan draws near, Kobayashi helps set up a farewell party so everyone can enjoy one last event together before Chloe returns to the United States.

Born and raised in the countryside of Japan, Hinako Hina Sakuragi gets anxious easily when she talks to new people—so much so that she resembles a stiff scarecrow. To overcome this, Hina hopes to get involved in theater, inspired by a play she saw during her school's field trip. So, Hina moves into the Hitotose Manor in the bustling city of Tokyo to study at Fujiyama High School, aspiring to join the school's renowned theater club. But to Hina's dismay, she learns that Fujiyama High's theater club has been on a lengthy hiatus. Having already come to Tokyo and enrolled in the school, Hina is at a loss for what to do next. Sensing her disappointment and eagerness to learn theater, Chiaki Hagino, the landlady of Hitotose Manor, encourages Hina to create a troupe with the residents of Hitotose Manor as its members. Hinako Note follows Hina as she begins a new life in Tokyo attending Fujiyama High while learning the ropes of theater with the support of her friends along the way.