Two members of the Sioux City city council are preparing for a trip to Japan to finalize a sister city affiliation with Yamanashi City. Councilman Tom Padgett will be joined on the excursion by Mayor Pro-tem Todd Moss. They leave Monday on the nine-day trip. Padgett says Yamanashi City will likely become Sioux City’s official sister city after this trip.Padgett says a sister city affiliation means more than just having city officials visit one another on occasion. He hopes for cultural exchanges and economic benefits for both cities. The state of Iowa already has a sister state affiliation with the Yamanashi Prefecture, a bond which celebrates its 40th anniversary this year.