It seems like this was the author's first serialized work, and her first work published in a tankoban format in 2009. Before that all she had was oneshots, which can be found in https://mangadex.org/title/52841/chihone-no-shanikusai . Though the oneshots in chihone were published in 2006-2008, they were never collected into a volume release until 2015.
With this series finished, the only collected volumes of sachiko that are not completely translated are chihone (megchan is working on it), Tokimeki no Ikenie (scanlator is not far behind), and Mashou no Shitatari (a comedy series). Not bad. Hope she gets licensed in English.