If you pause the the video at 1:56, you can see the cover (upside down) of the only book he goes out of his way not to show us....Therefore, I screenshot it and then flipped it in paint. Seing the dark cover, the two views of a semi-circular large building like structure, and the main attraction, that bird with a redish head and distinctive crest (although the beak doesn't look right) Still, it insantly reminded me of:
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If anyone can read that Japanese writing at the top, it may give us a clue to what it really is for sure! It looks like mostly kanji at the beginning with a few katakana leters at the end (so *something* i wo?)