Short-Short: Behold the Spirit Bird of Black Feathers

In that country, there exists a spirit bird known by the Japanese name Kuro-tsubame, or Black Swallow.
Because it flies only at night with jet-black wings, no one has ever seen its form.
However, because pitch-black feathers are found after it flies through the sky, its existence has been believed in since ancient times.
Furthermore, people who have become lost in the forest have recounted experiences of feeling a powerful wind blow from directly above, followed by pitch-black feathers falling down, which is also believed to be the work of the Black Swallow.

The Black Swallow is called a spirit bird because good things actually happen.
Its pitch-black feathers contain a great deal of moisture and plant seeds, and when they fall onto parched earth, vegetation begins to grow from them.
That vegetation bears many fruits, which become food for many living creatures.
In this way, the Black Swallow has saved people from famine many times in the past.
There is even a large-scale forest region known as the Forest of the Black Swallow.

In modern times, a project was launched to directly observe and, if possible, capture the Black Swallow.
Based on the sighting information gathered so far, it is believed that the Black Swallow's nest is on the mountainside of a certain mountain.
The assembled researchers installed numerous devices capable of observation even at night and waited for the appearance of the Black Swallow.
It did not appear for a long time, but two months after beginning observations, black feathers were finally found around the mountain.
The researchers, unable to contain their excitement, checked the recorded video.

The first thing seen was the trees of the forest creaking as if a typhoon had arrived.
The next thing seen was a giant bird that appeared as if to cover the sky.
Its size seemed comparable to a small passenger airplane.
Its appearance was similar to a crow, but its tail feathers, which accounted for half of its body length, were unique.
It seems that the black feathers fall from these tail feathers.
The Black Swallow rested for a while on the mountainside before flying off somewhere else.

After watching the video, the scientists were so moved that they were left speechless.
And they felt ashamed of themselves for having thought of things like "if possible, capture it."
Everyone felt a sense of awe at the overwhelming presence of the Black Swallow.
Questions typical of scientists, such as "How does such a giant bird fly?" and "What does it eat?" came to mind one after another.
However, everyone felt that this spirit bird was an existence that science should not touch.