GUTS-MAN is a brand of sturdy, highly functional socks made in response to demand from members of the Japanese Self-Defense Force. GUTS-MAN socks are actually used in the rigorous training of the SDF, and are even now an important part of their gear.

Quted from JGSDF HP

The toe socks, a particular favorite of the SDF members, are a culmination of the skills and knowledge of the many Japanese craftsmen under our umbrella—a long-standing sock manufacturer with over 90 years of history.