One of three books in the "Ideatity" series, this one by the Japanese illustrator who usually goes by the name Studio-Takeuma / a very nicely made hardcover book recently published by Bou Bow in Japan. It is 5.25 x 7 inches, 128 pages.
These copies were signed/doodled in by Takeuma (see the 2nd to last image here). There is some overlap with their Hedgehog's Hug book, but I recommend both books.
Search 50 Watts for Ideatity (they combined the words "identity" and "idea").