Kamon Database – Gegyo
Figure: roof gable decoration. 懸魚
A gegyo is a decorative wooden board used to cover the ridge and purlin ends on a roof gable. It is believed that gegyo were originally carved in the shape of fish as a charm against fire, and were introduced to Japan from China. (more information on JAANUS)
The Gegyo mon is very rare emblem. It is said that the Yūki clan was once using a Kikyō (ballon flower) mon, but when Akechi Mitsuhide, who was also using a Kikyō mon, betrayed his lord Oda Nobunaga, the Yūki decided to change their emblem in order not to be associated with the traitor. They then created a 6-leaves design that resembled to a gegyo. The Mizuno clan and its branches also use Gegyo emblems.
For more information about Japanese heraldry, follow this link.
About Kamon design, follow this link.