In all the world, Gensen (根森 
, Gensen 
) is quite a rare primarily boy's, but very seldom feminine first name. The first name Gensen is habitual in Japan, where it is a rare masculine name, China, where it is a very rare predominantly male, but scarcely girly name, and Tanzania, where it is a very rare masculine name. In absolute terms, it is the most numerous in China, Japan, and Philippines. Much less frequently, Gensen is the last name as well as the forename.