Protagonist is a thing/item/object and not a human/animal/spirit

Like the title :) A protagonist who is a thing. I'm accepting the spirit version as long as he or she is bound to a physical object. 

• Absolute boyfriend (ML is a robot)
• Kekkon Dekinai ni wa (not really sure if this fits, but the ML has a doll that he loves though there's also a FL, but the doll appears in every episode and does play an important role)