Riko Matsumoto

She heads Team C which is composed mainly 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" was a reference from 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 Team's Commander and Radio Operator.