Ore ga Heroine wo Tasukesugite Sekai ga Little Mokushiroku!?

A boy named Rekka Namidare experiences a normal life until his sixteenth birthday, when a girl from his future arrives to warn him of an impending interstellar war. He discovers he belongs to a bloodline fated for constant conflict. Each time a heroine faces a dire situation, Rekka is given an opportunity to rescue her. Over time, his repeated acts of saving numerous girls lead to a future where their intense jealousy triggers an apocalyptic event.