If you have too much transit time, you can go to Sakura no Yama Park where you can see the airplanes landing and taking off.
my favorite is the cherry blossoms season from the last week of March and the first week of April every year depends on the weather.
The Park is only a mile away from the airport and only 5 minutes by taxi from the airport. If you want to walk, it will be about 30 minutes but be sure you have enough transit time then!
