Yoshifumi Nitta, a yakuza member, is celebrating the successful acquisition of a prized vase for his collection when he is rudely interrupted by a large, peculiar capsule that suddenly materializes and falls on his head. He opens the capsule to find a young, blue-haired girl who reveals nothing about herself except her name—Hina—and the fact that she possesses immense powers. As if things couldn't get any worse, she loses control and unleashes an explosion if her powers remain unused. With no other choice, Nitta finds himself becoming her caregiver. To allow her to use her powers freely, Nitta asks Hina to help with a construction deal, which proceeds smoothly. However, during this time, a rival yakuza group covertly attacks his boss. To Nitta's shock, his colleagues later pin the blame on him! Tasked with attacking the rival group in retaliation, Nitta steels himself and arrives at their hideout. But suddenly, Hina unexpectedly steps in and helps him wipe out the entire group. It turns out that Hina might just become a valuable asset to Nitta and his yakuza business, provided she does not use her powers on him first! And so the strange life of this unusual duo begins.