why is it called unagi pie?

hubby brought this back from his workplace.... someone bought it from japan but none of his colleagues are interested to taste it.....

can u see that? it's called unagi pie but it had no unagi in it at all....... it is just a crispy snack with some sugar on it.... taste not bad......

by the way, i do not eat unagi (eel)... it taste so funny..... the other way round, dear hubby loves unagi a lot..... yucks!!!!