When Seto was little he saw a wedding with the groom carrying the wife down the walkway, the thought that it was a prince and a princess. One day (they were about 8) Kido fell asleep on a couch and he wanted to wake her up and take her to her room, instead he picked her up and started to carry her to her bed like the groom had done. Only, taking he was still a small kid he ended up almost dropping her, instead he fell on his butt to keep her from getting hurt. (When they get older he actually starts to carry her to her room when they are alone- per her request-)