Uusi Salainen kerho 4 (the New Secret Club 4) book for native language and literature published originally by WSOY has also been published in Japan. The series of book is targeted to students aged from 9 to 12 years. It has been widely used in Finnish schools.

The students in Finland have recently received good results in international PISA survey which has raised interest also towards Finnish learning materials.

WSOY is part of the SanomaWSOY Group.