Sora no Kane no Hibiku Hoshi de

The ringing of the bell from the blue moon, the "auspicious pillar" floating in the sky... In a particular season of the year, melodies similar to bell rings could be heard throughout the planet. A gigantic, floating pillar exists in this world, which is known as the "auspicious pillar". It has been rumored that around midnight, the figure of a young girl would appear near parts of the "auspicious pillar". To investigate this rumor Ferio decides to pay the pillars a visit and in front of him appears a young girl who is oddly dressed. History is written through the encounter of the boy and girl. (Source: AniList)