1000 Yen Hero

1000 Yen Hero summary:

Kaijin are attacking! But luckily for the people of Japan, heroes are there to protect them, with powers that run on a rate of yen per second. For Hiasa Sen however, there are much more important things to worry about, like catching sales on groceries, and his many part time jobs, all to take care of his little sister. When danger approaches however, he has a secret power of his own, but it may be more trouble than it's worth.