http://sakhrest.ru/arhiv/badminton.html They have a local federation since 2007, they organize regular tournaments (latest tournaments took place in November-December 2013, look here: http://www.sakhalin.info/news/88283/) You can probably try the following address in Yuzhno-Sakhalinsk (School #22 at Purkaeva Str., 78A) or call 61-40-01 (Yuri Vasilyevich Komyshev).