Hyakko

Kamizono Academy is a school with an elementary, middle, and high school all within the same campus, and Ayumi is a new student at this enormous school. She is shy and has difficulty making friends, but when she meets wild and outgoing Torako, school life gets interesting as Torako begins to befriend various students within their class. It appears that the series stops at 6 volumes in 2011. Then the first 6 volumes were reprinted in 2012 with a 7th volume that came out in 2013.