All Digital Editions of the Manga Have Been Delisted as of 2019

(from ebookjapan):
Mimi, who came from Sasayama in Tanba to her aunt's house in Tokyo, is big and strong. She is strong and gentle, and everyone calls her "Kintoki-san". At her new elementary school, Kintoki-san is bullied by a group of five bullies, including a rich boy named Okawara-kun, because of a trivial incident. However, when he is punished, Okawara-kun tries to unfairly bully Kintoki-san every chance he gets. ...... Shotaro Ishinomori drew this story of a courageous girl under the penname "Teiko Minami" for girls!