Joe Carpenter is refered to as "Joker" for most of the time. He is in charge of everything. He runs "Section A Special Library Force" that's trying to retrieve the Kikou Books. He is the main person in charge of the missions for Yomiko, Nancy, and Drake. Joker works very hard. He is very smart, but not very nice.

Joker is always stressed, some of it caused by Yomiko. ^^;

Joker knows that if you want Yomiko to listen, you have to take the book she has, then she will do her job. He plays this trick on her so that she will be motivated. This isn't a bad trick, Joker knows that this is how Yomiko works.

The name, "Joe Carpenter" could refer to Joseph (Jesus's father) who was a carpenter. Joseph of Nazareth, or Saint Joseph is a figure prominent in Christianity, from the New Testament who was husband of Mary and thus foster-father of Jesus. Perhaps a stretch, but Junior could represent the "Jesus" whom Joker is trying to foster to be a savior for mankind.

As for "Joker," the Joker can be an extremely beneficial, or an extremely harmful, card. In Euchre it is often used to represent Benny, the highest trump. In poker, it is wild. However, in the children's game Old Maid, a solitary joker represents the Maid, a card that is to be avoided.

The Joker is often compared to 'The Fool' in the Major Arcana of the Tarot deck. They share many similarities both in appearance and play function; the Fool is often the highest trump.