The character Korosho, a spirit of a randshell backpack, is from Benesse’s Shinken Zemi Shogaku Kōza correspondence course for early elementary schoolers.
Korosho first debuted in 1998 in Benesse’s Challenge textbooks for its Shinken Zemi Shogaku Kōza correspondence courses.
The anime film Eiga Korasho no Kaitei Wakuwaku Daibouken!
The tiger character has starred in multiple anime series and films, including a film slated for next March.