Artist's commentary
Hang in There, Kogasa-san 2568
I can't draw any of the specifics for this riddle-solving, so it maybe tricky to understand the difficulty from the strip, but when I got the final answer, I collapsed to my knees. :-)
I got some seriously good exercise, walking the inside of Shibamasa World from end to end. I took over 20,000 steps!
You apparently get a cheap prize when you solve the riddles, but what you can get became a new mystery. The next time I go, I'll arrive at the answer in five minutes! :-)