After the events of the war and Kiana Kaslana and Raiden Mei reunite finally, the two settle down in a simple life without much worry with a 4th Honkai Impact. Though their simple life didn't last very long as a strange increase in Honkai Energy was detected inside St. Freya High. A large beam was shot down onto the centre of St. Freya High and what Mei and Kiana found in the centre shocked the both of them to the core.