In the manga, Cain's personality is drastically different. While mostly demonstrating an almost childlike, carefree nature most of the time, he was also shown at one point yelling in an over-the-top manner at a vendor who, in his opinion, made poor fish and chips. He has a seemingly random encounter with Esther while she is having an uncomfortable and undesired meeting with a reporter in London. During this encounter, she mistakes him for Abel at first due to their similarities in appearance and manner, though he is dressed in a white suit and a white top hat. He follows her around for some time while she attempts to make her way back to the Royal Palace, all the while acting in an even more frivolous and goofy manner than Abel. Finally, Esther runs into Isaak, posing as Mr. Butler, who tells her that he happens to be looking for someone. This someone is revealed to be Cain who, after listening to Esther telling Issak that she is lost, insists on driving her back to the Palace. When Esther asks him for his name, he momentarily adopts a more solemn manner, and tells her that his name is Cain. The situation resolves itself without any incident, with Cain delivering Esther to the Palace safe and sound and then going on his way. In the manga, Cain seems to be very concerned with Abel's well-being for some reason; he shows great happiness when told by Isaak that Abel is well after his confrontation with Dietrich in the Byzantium nuclear launch facility, and during said confrontation, Dietrich mentions that "a certain someone" would be furious if he was to kill Abel. Why Cain shows this concern is not known.
