The fourth season of Date A Live. 
 
Despite the numerous challenges he has overcome so far, Shidou Itsuka's mission with Ratatoskr is far from over. In a departure from his daily routine, Shidou encounters a starving woman lying on the street and ends up helping her. After the two arrive at her apartment, the woman introduces herself as Nia Honjou—a popular manga artist working under a pen name. However, cutting straight to the chase, Nia reveals that she is also a Spirit and is aware of Shidou's secret operation. 
 
Interested in seeing his charisma firsthand, Nia challenges Shidou to win her over on a date. As he strives for an opportunity to seal her powers, Shidou learns more about Nia and her history with Deus Ex Machina Industries, a name he is all too familiar with... 
 
(Source: MAL Rewrite)

The first part of Date A Bullet.
 
Hibiki Higoromo, better known as, Empty, is an amnesiac young girl. She wakes up in the neighboring world, where she encounters Tokisaki Kurumi. In order to kill the mysterious girl, Kurumi leads Empty to a school. When arriving at the school, a number of girls, known as semi-spirits, gather together. Now then, a new battle begins. (Source: Wikipedia)

Hot Game Studio