There is a problem with Shiranui katanagami, you cannot revive him with cards that bring zombies.
Even with your very very limited information you have provided. Can I take a guess, and say that you probably didn't properly summon the card in the first place? i.e. using Youtou's effect in the graveyard to summon him, which is not considered a proper synchro summon, therefore you cannot summon it from the graveyard later.