The somewhat precocious and sadistic girl Mitsuba, the somewhat lecherous muscle girl Futaba, and the somewhat mysterious gloomy girl Hitoha. Better known as the (mischievous) "Marui Sisters," this is the story of how these triplets go about their days in Class 6-3 with their cute yet wild antics.
Chitose Morishige is a 12-year-old seventh-grader without a friend in the world. Her father, Professor Morishige, built a robot companion for his daughter to ease her loneliness. The only problem is that Ichika Robata, the android, is so lifelike that Chitose believes she's a normal human girl who either ran away or was kidnapped by her father. Ichika attempts repeatedly to prove that she's a real robot, with hilariously disastrous results.