Things you can find in Horikoshi's desk/office: -Fanart/fan letters on the walls -The anime sheet reference of Uraraka's costume (ref figures too) -Showcase of BNHA vol. 25, vol. 18 and vol. 29 (EN version) -A note saying "Deliver the Name on the 9th" (chapter came out on the 16)

A better look at the bonus Uraraka illustration that comes with TUM vol. 6 drawn by Yoco Akiyama.

Horikoshi's illustration and comment in TUM vol. 6: "This is 'Sleeps like a log in spring-chan' [Zucchan]. Weak. Seems sleepy. If you want to defeat him, do it now." Hori used an expression from an old poem "In spring one sleeps a sleep that knows no dawn"

Vol. 40 came out along with TUM vol. 6 so Akiyama and Horikoshi traded art with each other. They both drew Kacchan.

The assistants, the people responsible for most of the changes you saw. The real heroes.