Ruka (流輝) is brewed by Matsuya Shuzo in Fujioka City, Gunma Prefecture, using water sourced from the Mikabo mountain range. The brand was created in 2009 when the brewery owner's son joined the operation — the name was originally a candidate for his child's name, and was given to the sake instead with the wish to nurture it with the same care as one's own child.
