High School DxD HERO

The fourth season of _High School DxD_. Issei and the 2nd years attend a class trip to Kyoto for well-deserved relaxation, leaving the senior and junior class students of the Gremory family behind. However, once there, they fall under attack and must win without Rias or their other powerhouses. (Source: Anime News Network) _Includes episode 0, Taiikukan-ura no Holy_.