Mugen Sekai no Amadeus

The story takes place in a world that is gradually decaying because of the approach of an "evil god" from another dimension. Seishirō Shikizaki meets Ajisai Misaki at a party before school starts, and the meeting feels predestined. The tagline in the magazine reads "Under the cherry blossoms, a 'hero', 'evil god', and 'weapon' meet." (Source: Anime News Network)