ゲンナジー・エドゥアルトヴィッチ・カワチエーワ

Gennady Eduardovich Kwachieev, also known as Gen (ゲンさん, Gen-san) is a member of Guardian. In the day he is a ramen shop owner. But at night he is a member of Guardian's elite Bayern Knights.

(Source: Rewrite Wiki)