Naruto Uzumaki has always loved the female ninja the Kunoichi so when he got his evil piece set he decided to have an all Kunoichi peerage even if he has to go to other worlds to do so.

Challenge rules

only 6 kunoichi at max from Naruto but none from Konoha

Starts 100 to 200 yrs before canon

Naruto is in a forgotten marriage contract with Rais (Forgotten from the Gremory side)

Yes it is a harem

The Uzumaki is one of the 72 pillar familys