Waga Tousou: Imouto no Tame nara Sekai o Shukusei Shite mo Ii yo ne!

Mina, a Lieutenant of the Space-Time Vanguard Unit arrives from the distant future to interrupt Ichikawa's peaceful life with some upsetting news of how the world would end-up if he continues to pursue his affection about his little sister. The sound of the grim news doesn't seem though to deter Ich