Tsukasa is an artificially created robot by inventor Rui. He has a very intelligent mind that is very difficult to distinguish from a human by character. He values ​​Rui as his creator and mentor. However, he is interested in why Rui does not constantly try to get closer and, as he understands, he reminds his creator of someone. Sometimes Tsukasa talks about emotions and strong affection, but Rui reacts to this somehow bitterly. Tsukasa assumes that this is due to a photo of Rui with a blond man