Marionette Company 2 Chu!

The protagonist, who apparently raised the original marionette from part 1 to near-human form, stumbles upon two abandoned marionettes named Marine and Maria. He takes Marine under his care; his obnoxious rival classmate Arese takes Maria. Arese insists marionettes are nothing more than robots with computer circuits for hearts. The protagonist, drawing on his experience with the original, is convinced otherwise and sets out to prove it.