Yotteru dake de dai shikkin

Kentaro Miura is the illustrator for the cover and sci-fi pictures.

There are also other artists. Most are under pseudonyms.
Miura's pseudonym is written in reverse with Japanese characters.
Akahori Satoroichi-sama あかほり さとろ一様 (Title)
Urotanke Raumi-sama うろたんけ らうみ様 = Kentarou Miura (p 5, 6-7, 15, 16-17)
Moriko~sama もりこ〜様 = Mori Kouji (13-14)
Odachin おだちん (26-30)
Akkiu あっきう (8-12, 23-25)
Yumemi Sugiko 夢美 寿祇子 (18-22)