Around Japan in 3 weeks

Hi,

I would like to know how we get to the places we would like to visit (by public transport). We would like the fastest way when possible. Also we will travel with our suitcases so we do not want to have many stopovers. Is this possible for our route? We would like to buy a JR railpass but I do not know if you would advice that.

We will arrive at Osaka Kansai Airport and we need to go too Yotsubashi Station for our hotel.
In Osaka we would like to see the aquarium
From Osaka to Hiroshima station
In Hiroshima we would like to visit the Wisteria flower tunnel
From Hiroshima to Kyoto Station
In Kyoto we would like to visit the bamboo forest and visit Nara
From Kyoto we will go to Nagano Yudanaka Station
From Nagano we wil travel too Tokyo JR Shinjuku station
Of course we will travel in Tokyo ass well.
From Tokyo we have to get back to the airport

I hope you can give us some advise!