A salaryman living alone in a small apartment is visited by complete strangers, a large family with grown-up sons and a daughter, who take over his apartment and his life. They use his money and he has to wait on them as their servant. They even steal his girlfriend. Although they behave very dictatorially, everything is decided "democratically" by the majority.

The organization Mighty Jack is formed to combat the criminal syndicate known as "Q", and are given a large array of advanced weapons, chief among them being a high-tech submarine. Harold Hatari is abducted by Q, and Mighty Jack is dispatched to rescue him. Hatari is interrogated and threatened with blinding lights, but the Mighty Jack crew rescue him in the nick of time. Later, Q is discovered to be using "hot ice" (water that remains solid at room temperature) to create weapons and a secret ocean base disguised as an iceberg (though it's not precisely clear how hot ice could be a major world threat). Q then attempts to take over the Mighty Jack sub.