What to wear during late March in Japan?

Could anyone please advise me what kind of clothing I should wear during late March thru early April in Japan?

I will be in Japan with my College from 29th March to 5th April. It is our first time visiting the country and I pick this time as we are hoping to see some cherry blossom.

We are coming from the United Arab Emirates, Dubai. I'd appreciate advice on what we should expect in terms of temperature and weather during that period.
should I carry with me winter dress with hat and jaket?!!

Thank you very much.

The temperatures vary considerably depending on the region from sub-arctic Hokkaido to sub-tropic Okinawa. Here are the basics:
http://www.japan-guide.com/e/e2273.html

should I carry with me winter dress with hat and jaket?!!


please advice

The average high temp in Tokyo is about 15.5 degrees celsius on April 1st. So it might be as cool as nighttime in Dubai in winter.

We were there in late March, early April a few years back. Tokyo was bitterly cold and windy, as was Miyajima. Nikko snowed. But by the second week of April it warmed up, and we had some very mild days.