At episode 10 of K-ON! 2nd Season, Sawako was ask to play a band on a wedding of classmate of hers, but she decline because it might destroy the teacher image that she work hard to built up. Somehow the K-ON! group was caught evesdroping by Norimi also known as Christina, whose a former member of the Death Devil and ask them to convince Sawako to play with the band, but they failed so there the ones will play on the stage in the wedding. After Sawako hearing them playing the song(that somehow have many mistake) got angry then take over the stage to show the true way to play the song of the Death Devil, then the crowd go wild. After that even her teacher image is ruined, she still popular to the freshmens.
I say, she go into wild mode, even she know what about to do was going to destroy her, but in Punk Rock Society, they have no care and no future just passionate heart hehehe.(well its not that I like her song)