Question: Miho Obana, is a shōjo manga artist born in Tokyo, Japan, her best-known work was "Kodoma no Omocha", also known as "Kodocha", which was published in Ribon, a monthly Japanese shōjo manga magazine published by who?
Sentence (from "Ribon"): The circulation in 2010 was down to 243,334.
Relevant evidence: No