Go shopping in Tokyo, Japan ~ What's the climate like in early June? Should I bring long sleeves or short sleeves?

Since I'm here for shopping ~ why do you still consider these! You can buy it on the same day. _ _ I bet you will regret taking clothes when you look at your overweight luggage back home ~ ~ ~

As for the climate, you can check the weather forecast of http://weather.yahoo.co.jp/weather/. and Japan, which is very accurate.