Jun is a character from K-On!
She shows up in Volume 1 Ch 13 of the manga; her hairstyle consist of two short twintails. She is a classmate with Hirasawa Ui and Nakano Azusa, and often hangs out with them. Ui tried to get her to join the light music club but ultimately failed due to a strange visit to the club room. However, she starts to regret it when she hears about all the activities the club does. She also has a pet cat.