in the interviews with Osano he said this:
Interviews with Fumio Osano
As popularity accelerated, many related products came out that weren't originally planned, but the popularity was far greater than expected.
"I was impressed when she made the Moon Stick toy, which is an object that appears in the second half of the first series. Ms. Takeuchi is a person who has a strong commitment to design, so she wanted to design it herself. However, Due to the busy schedule of the manuscript, it was difficult to start designing it and in the end, if we hadn't started making the molds tomorrow, we wouldn't have been in time for the end of year sales season, so in a bar at midnight I made her draw an elaborate design on a paper napkin, Mr. Bandai's responsible person who was present took the napkin and handed it to an Osaka merchant with the first Shinkansen of the morning, and managed to get things done.