ぽっぺん先生の日曜日 (Poppen sensei no nichiyoubi, Dr. Poppen's Sunday, 1973) is a children's book by FUNAKAZI Yoshihiko (舟崎克彦, 1945-2015). It's a comical fantasy story in the tradition of Alice in Wonderland, but with an adult protagonist, the biology lecture Poppen, who gets trapped in a riddle book and must go through all the pages to find his way back to the outside world.
