Riko Matsumoto

She heads Team C which is composed of Reki-jo (History Buffs), which is also called "Hippo Team." Her team operates a Sturmgeschütz III or more commonly called "StuG III."

It is suggested that her name "Erwin" is a reference to Field Marshal Erwin Rommel, a German general during WWII.

She is really into the history of Europe, especially Germany. She's personally biased towards World War II.

She serves as the team's commander and radio operator.

(Source: Official character sheet, ANN)