The movie is a compilation of episodes 1-8 of the 2017 television series with new scenes added for the introduction. It covers the period from when Riko descends into the Abyss with her robot companion Reg, reaching the second layer where they meet the White Whistle Ozen who reveals information about Riko's mother. (Source: Wikipedia)

The movie is a compilation of episodes 9-13 of the 2017 television series. Riko and Reg descend to the third layer where Riko has her first experience of the Curse. They descend to the fourth layer where Riko's arm is injured by an Orbed Piercer and Reg tries to save her. Nanachi comes to their aid and saves Riko's poisoned arm. In return Nanachi asks Reg to kill her immortal companion Mitty. Nanachi then joins Riko and Reg in their quest to reach the bottom of the Abyss. (Source: Wikipedia)

Continuing their perilous descent down the Abyss, Riko, Regu, and newfound friend Nanachi reach the Abyss' fifth layer, The Sea of Corpses. Upon arriving at the research station known as Idofront, the main trio encounter the mysterious Prushka, the alleged daughter of Bondrewd, who leads them to the White Whistle responsible for Nanachi's dark past. Despite the welcoming appearances of Idofront's residents, Nanachi warns the young adventurers that things are not always what they seem. With the only route to the sixth layer shrouded in mystery and Bonedrewd's schemes awaiting them, what sacrifices must be made in order to continue the journey down to the bottom of the Abyss? [Written by MAL Rewrite]

While investigating a sound anomaly across the galaxy, Basara crash-lands on a snowy planet and receives an unfriendly welcome from the local residents. On the planet, he befriends Pedro, a four-year-old boy who watches the Galaxy Network and idolizes Fire Bomber. Basara also discovers that the sound he's searching for is generated by Emilia, a lone Meltrandi struggling to make music of her own. (Source: ANN)