°·..·°¯°·._.· Disclaimer ·._.·°¯°·..·°
The soundtrack comes from an anime called “Fantastic Children” (ファンタジックチルドレン) created by Takashi Nakamura and produced by Nippon Animation.
Wikipedia:
https://en.wikipedia.org/wiki/Fantastic_Children
Anime News Network:
https://www.animenewsnetwork.com/encyclopedia/anime.php?id=4241
You can find this specific track in the series’ official O.S.T titled “Fantastic Children: A Gift from Greecia” (ギリシアからの贈りもの) composed by Kōji Ueno.
I own nothing but the video editing.
°·..·°¯°·._.· Trivia ·._.·°¯°·..·°
The video background comes from a scene in episode 2—”Wandering Memories” (彷徨う想い) when Professor Wilhelm Conrad Röntgen recalled the meeting with a strange white-haired, blue-eyed girl. It was a very good scene in my opinion.
If you have time, please check the anime out!