The twin giant baby is called Yuki Mina and Reiko Mina. This supernatural power makes them be hopeless and annoyed. If they can live an ordinary life, they will be more happy and excited to live in this world. Unfortunately, this power cannot bring good things but bad luck. The first bad luck is their parents died and they cannot prevent it because they are still small and weak.
They wish this power never brings bad luck again in the future. Bad luck makes them be sad and regret everything. So, they hope this power will bring good luck to others such as saving others' life and preventing from bad things happening. And then, the twins will be happy and proud to have this power.
Their stories are not going smoothly as the waterfall flows from high to low but the enemies will become to them one by one. It is a disaster for them but they will work hard together to save this life from that monster. They believe that they can fight the monster by themself and find a way to stop the monster. Although it is difficult, they believe their power is strong enough to beat the monster.