"Nihongo Sou Matome" is a popular Japanese language learning textbook series published by JSR (Japan Supporters of Rookies). The series aims to help learners prepare for the Japanese Language Proficiency Test (JLPT) and improve their overall Japanese language skills.
This clearly refers to the purple N4 book(s) in the series. Nihongo Sou Matome N4 Pdf 319l
