Just as the Moroboshi family is settling down and coming to grips with the idea that their luckless son has married into an extraterrestrial clan, a peach-shaped package arrives from (literally) out of nowhere, through the large hole it punched through the roof. Mrs. Moroboshi wonders how it tastes. Ataru wonders where it came from. Mr. Moroboshi wonders how he's going to pay off the mortgage now that there's a new repair bill looming. Lum's happy -- it's her infant (but streetwise) cousin, Jariten, or "Ten-chan" for short, coming to live with her and her new husband. And he breathes fire! Soon, Jariten's playing with the local fauna, and discovers that his alien candy has some interesting effects...