Wandering in the bamboo forest one day, a boy runs into a girl in a make-shift cloth bikini fighting a panda that seems to dodge every one of her attacks with the greatest of ease. Mortified, she attacks the boy.
Fortunately, he is a ninja.
Welcomed by his ninja parents, the girl reluctantly admits that she is an alien lifeform grown inside a stalk of bamboo; intended to spring forth full grown and capture the hearts of the planet (for strictly information gathering purposes) she has instead popped out aged twelve on account of the ninja panda attempting to eat the bamboo she was growing in.
While she quickly settles into a role as a star performer in the ninja clan's ninja village amusement park, they do run into some trouble with the local men in black, a regular thorn in their side since the head ninja was kidnapped by aliens in the color pages to the first volume in Narita Ryohgo's increasingly batshit short story collection series.
The second story in here takes Narita well outside his comfort zone, pleasingly -- the story of a man who only wants to pilot a giant robot, and thus becomes a robotics engineer for the express purpose of building a robot for himself to pilot. Problem is, just as his life's work is about to be completed, the company is bought out, and the new president wants to replace him as the test pilot with a fourteen year old child actor. (Because: Eva. Not named, but Narita says, "I don't need to, do I?") Eventually the man's opinion changes when the child actor sneaks into the factory to sneak a look at it, and he finds the boy standing in front of the robot sobbing openly at how fucking amazing it is. (The boy even admits to acting cool about the idea on TV because that's what a robot pilot would do.) Also features Hariyama's high school aged daughter for the first time...in a small supporting role, of course.
The third story is another in his urban legend series -- this time focused on the men in black. A woman wakes up in a park dressed in a black suit. She has no memories, but slowly begins to piece things together...and realizes that she was part of a group of con artists posing as men in black to scam money of the bizarre shit that happens in town, but that they wound up falling prey to an actual group of aliens...that all wear black.
While there is no big cross over story this time, he does toss in a few page long epilogue which reveals that the ninja kid is friends with the robot pilot and that the alien kid from the third story is friends with the Hariyama boy.