09 is the 10th Episode of the parody series, Youjo Shenki.
Tanya Degurechaff and Viktoriya Ivanovna Serebryakov are in a room discussing about the recent food poisoning incident. Warrant Officer Teyanen retired from the battlefront due to a rotten potato. Then, Tanya asked Visha if she tell the differences between a normal and rotten potato. Visha stated that the only way she can tell the differences between the two is by the taste.
Therefore, Tanya have to teach her the correct way to recognize a rotten potato. She also told Visha the after effects if one consumed a rotten potato. Due to the names of the poisoning being similar to the names of people in the Russie Union, Visha accidentally spreaded false rumor and alerted Matheus Johan Weiss about it.