According to the urban legend of the 4:44 ritual, using a radio player in front of the Akeyuki Sacred Tree can transport individuals to a different dimension. As part of their Crystal Radio Research Club activities, Asuka Tsuchimiya and her friends Nana Nanase, Mia Silverstone, Yuu Tounaka, and Chloe Morisu decide to put the legend to the test. To their astonishment, the ritual succeeds, and they find themselves in a new world. This world has a version of Asuka with a distinct personality and fighting prowess, nicknamed Seriouska. Seriouska reveals to them that the parallel worlds are threatened by the Twilight, a force that extinguishes all possibilities. In an effort to stop the Twilight King's reign over the multiverse, Seriouska seeks his demise and urges the girls to find him while embracing their true selves. As they hunt for the Twilight King, the girls discover that the solution to their fight against the encroaching Twilight may be closer than they think.