Shōjo Comic
A ten volume spin-off series focusing on Yori's upperclassmen Takuma Kakinouchi and his childhood sweetheart Mayu Taneda was serialized in "Shōjo Comic" from December 2005 through August 2008. It is called Boku no Hatsukoi o Kimi ni Sasagu (abbreviated to BokuKimi) and means "I Give My First Love to You".