Kyouji is a scientist who had one dream: to create a robot that could help, support and snuggle up with humans. However, he was fed up with the recent trend of people being wary about the dangers of robots with AI, so he created robots with ‘hearts’ instead. As the first step towards a future where humans and robots can co-exist, he began to live together with these three androids, the domestic Lux, the curious Sphere and prototype Nect, while watching over their growth.

However, sometimes Lux would barge into the bath to wash his back and sometimes Sphere would crawl into his bed. As a scientist, he was delighted at their displays of emotion, but on the other hand, it was somewhat embarrassing and troublesome for him as a member of the opposite sex.