Plugoodo background proposal:
His goal was to support various sources of energy worldwide. He was living in peace, working hard and doing his best. The reason he attacked the three girls is that Dou wanted to destroy him, because of one big traumatic past: her entire childhood. Dou went that far as to use her family to justify her heinous acts.
Nice job dooming energy sources Plugoodo supported, Dou. Everyone will be in despair. Do you feel like a hero yet?