"Yggdra Union" had a small development team, consisting of less than 25 members. Shinichi Ito, director and designer of Riviera, played the same developmental role in "Yggdra Union". Also reprising their roles are composers and sound designers Minako Adachi and Shigeki Hayashi. Masanori Ishikawa, one of Riviera's programmers, returned to be one of the two "Yggdra Union" programmers. Riviera's character designer, Sunaho Tobe, managed the card illustrations, with Satoko Kiyuduki taking on character design. Sting also contracted Atlus USA to write English text for the Japanese version's script.