Keiko Tobe was born in Amagasaki in Hyougo, Japan. She graduated from Kwansei Gakuin University's School of Economics and took an advertising job thereafter. When her then-newlywed existence required her to move to Tokyo with her husband, she began working as a mangaka's assistant and eventually became a mangaka herself. Though she has published numerous (primarily mystery-oriented) manga through Akita Shoten, which also published her 1986 Princess magazine debut, Hikari to tomo ni... is universally considered her masterwork. Tobe-sensei lived in Japan with her husband and two sons.
source: http://catdir.loc.gov/catdir/enhancements/fy0803/2007299825-b.html

Died on 2010-01-27 at the age of 52.

http://www.animenewsnetwork.com/news/2010-01-29/with-the-light-manga-creator-keiko-tobe-passes-away