Based on the second trailer, the first arc will be an answer arc to Onidamashi-hen, with Mamiya Rina making her appearance in the sequel series. Sotsu continues the story of Higurashi no Naku Koro ni Gou, following Satoko Houjou as she attempts to stop Rika Furude from leaving Hinamizawa.

Masane Amaha and her daughter Rihoko are on the run from a government child welfare agency that wants to take Rihoko away from her mother. They are caught and Rihoko is taken away. Meanwhile, Masane is attacked by an advanced weapon that can disguise itself as a human being. When faced with the danger, a strange light emits from her wrist and she transforms into a powerful being. She destroys the weapon and consequently becomes involved in a power struggle between powerful organizations, with her at the center of their attention. Because she holds the greatest power of them all, the legendary Witchblade. (Source: AniDB)

Bundled with the limited edition of Blu-ray/DVD of Boruto: Naruto the Movie.

Having decided to walk down a path separate from their inspirations as idols, the girls of Aqours are more determined than ever to shine brilliantly as school idols. With their previous performance marginally increasing the number of prospective students for their endangered school, they look to carry the momentum of their small step forward into the school's upcoming open house and the next Love Live competition. Hoping to use these events to bring more attention to their school, the nine girls look to give their best performances yet. Unfortunately, these small steps forward are not enough to convince Mari Ohara's father from changing his plans. Undeterred by Mari's pleas for reconsideration, the decision to close down the school is made official, putting an end to Uranohoshi Girls' High School's student recruitment, including the open house. Though all hope seems to be lost, the school idols refuse to give up. Faced with impossible odds, Aqours sings, dances, and shines in the hopes of bringing about a miracle. [Written by MAL Rewrite]