BLUST!

Blust! summary:

A one-shot from the artist of Eyeshield21, published in Shounen Jump 2009 #22-23 Hokazono Kai, a soldier amidst a nuclear war, was captured by the enemy during a rescue mission. As a captive, he was tortured and tested upon. When the research center is hit by a tsunami and he escapes with a pair of blasters for arms. Kai returns to the japanese military and uses the one-of-a-kind weapon in battle under the codename "Blust".