Ao to Kuro no Kyoukaisen

On the 81st day of the Stellar Calendar year 1993, a massive explosion in the city of Nowal released a black smoke screen that blanketed the world, causing rainfall to drastically decline. The planet became known as "The world where rain does not fall." About a century later, a witch who took control of the rain is called the "Rain Girl." A young man, known as the "Clear Boy," approaches her as a destined partner. The story begins after these two incompatible individuals meet.