Lime, Cherry, and Bloodberry, female-like androids called marionettes, have returned to Otaru`s side. The somewhat reformed marionettes of Faust (Tiger, Luchs, and Panther) are sent to stay with Otaru and friends to learn more about being human. Enter a seventh marionette named Marine, who has a mysterious power -- and they all possess the special maiden circuit that allows a marionette to feel emotions!

(Source: AniDB)