Nineteen-year-old ronin Hideki Motosuwa desires two things more than anything else: a girlfriend, and an expensive humanoid computer (known as a 'persocom'). But with his dead-end job and no financial aid from his parents, owning a persocom seems impossible... until he finds a blond-haired female persocom tied up amongst a pile of trash! After getting her home and figuring out how to activate her, even the computer-illiterate Hideki realizes there is something unusual when it appears she can only say one word - Chii. Is she just broken, or is there more to this persocom than her behavior lets on?
If you like the idea of possible human/robot romance, but was disappointed by Heavy Mecha Blue's quick ending, I recommend you check out Chobits. It's one of the best manga for dealing with love and robots.