Iga-Ueno is located between Ōsaka and Nagoya, it is reachable within 3 hours from both these cities. It is possible to visit Iga-Ueno on a day trip, but the public transportation is limited, so check in advance!
First, go to Nagoya Station by Shinkansen. Then, there are three ways to reach Iga-Ueno:
The first one is travelling on the JR Kansai Line. Departing from Nagoya Station, at Kameyama terminal take the train to Ōsaka or Kamo, and get off at Iga-Ueno Station. This journey is totally covered by the Japan Rail Pass, but remember that you cannot ride the Nozomi Shinkansen.
At Iga-Ueno Station transfer on the Iga Railway Line and get off at Ueno-shi Station.
The second way consists in using the private lines of Kintetsu Railways. You can get to Iga-Kanbe Station directly; depending on the case, you may have to transfer at Ise-Nakagawa Station. At Iga-Kanbe Station take the aforementioned Iga Railway Line and get off at Ueno-shi Station.
The third way is travelling by bus. There are 10 Mie Kōtsū buses per day heading to Iga-Ueno from Nagoya. Meitetsu Bus Center (where the bus leaves from) is close to Nagoya station.
Arrived at Iga-Ueno Station, follow the directions as written before.
Mie Kōtsū also offers a direct night-bus from Tōkyō. The fare is around 7.500 yen, 13.500 yen for a round-trip.
There are three ways to reach Iga-Ueno from Ōsaka:
The first one is using the Kintetsu Railways. Get on the Limited Express heading to Ise-Nakagawa Station or Nagoya Station from Ōsaka-Nanba Station and get off at Iga-Kambe Station; the journey takes about 1 hour. Transfer then to the Iga Railway Line from Iga-Kambe Station and get off at Ueno-shi Station.
By taking a Kintesu-Ōsaka line’s Express train from Ōsaka Loop Line Tsuruhashi Station, the journey requires 1 hour and a half but the price decreases, as the train is not a Limited Express.
Another way consists in travelling on the JR lines, and this one is so covered by the Japan Rail Pass.
Form Ōsaka Station or Nanba Station, take the Yamatoji line heading to Kamo Station. Here transfer on the train heading to Kameyama and get off at Iga-Ueno Station, then take once again the Iga Railway Line to Ueda-shi Station.
A third route is the bus. There are six Mie Kōtsū buses per day leaving from Ōsaka. The journey takes 1 hour and 40 minutes.
The buses leave from Shin-Ōsaka (useful if you arrive in Osaka by Shinkansen) and Umeda Stations.