Io learns that his father used the know-how of space colony construction to build this: humanity's largest terrarium in history. The trip to Jupiter changed Otto. Someone had to protect the fragile planet. Humanity has foolishly devoured it...
It is interesting how there's apparently some continuation of sort to the Azieru line (though a million funnels is bananas).
It's likely some far-flung U.C. setting after some intergalactic space war or something, but that's for anyone to guess.
Billy makes quick work of the enemy, but he's still hoping his MSN-01 responds to his thoughts (I see he's still doubtful!).