HBD

HBD is a disease from the Mega Man Battle Network series. There are 2 known cases of it, the first case died, the other one survived. Symptoms include severe chest pain, being unable to breathe, and cutting off sentences by an HBD attack. It is so rare, the only place they could've tested Mamoru or Hub for HBD was at Seaside Hospital. There are no antibiotics as a virus could not have caused Mamoru or Hub Hikari to hsve such severe chest pain. The only treatment and possible cure is surgery, but the procedure name is never revealed.