Rumi

She is first seen along with her two teammates in an M4 Sherman watching Alice Shimada's training match.

During the fight against Ooarai's Composite Team, he commands a company of seven M26 Pershings (including his tank) and one M24 Chaffee. Rumi Company engages Dandelion Team in a long-range firefight across the wetlands with the goal of containing them. The company retreats after Ooarai destroys the Karl-Gerät 040 artillery.

She is later seen chasing the Panzer IV and the Hetzer through a maze with two Pershings and a Chaffee. After the two Pershings are eliminated, Rumi spots the CV.33 on the roller coaster as a spotter and presumably sends two Chaffees after it. She later reunites with her two comrades to form the "Bermuda Trio", taking out Saunders' tanks before being rammed by the T-34/85 and shot down by the Tiger II, seconds before Azumi in turn shot down the Tiger II.

Her last appearance is in Das Finale 3, where she watches the match between Continuation and Saunders along with Megumi, and later watches the match between Continuation and Ooarai

Appearance: Rumi is a short girl with platinum gray hair and platinum blue eyes, wears glasses, and is usually seen wearing the sensha-do uniform of the University Selection team.

Personality: Little is known about his personality during the film, it is known that he is part of the so-called Bermuda Trio along with Azumi and Megumi.

In the Drama CD it is revealed that she was a student at Jatkosota High School before going to college, like her 2 teammates she doesn't know how to cook, she is a terrible cook, she is a party girl who likes to drink and shows a lot of emotion for the tenderness of her commander.