Doubt!!

Viz Book Description: "Ai Maekawa is unremarkable, unpopular junior high school girl. As a shy anime geek, she spends her life in total anonymity until one day she gets "pantsed" by a girl named Yumi - right in front of Ai's crush, Oshita - revealing Ai's "Cutie Bunny" granny panties! Utterly humiliated, Ai remakes herself completely before entering her new high school, where she plans to leave behind her past life as a nobody and be one with the popular, socially acceptable students. And it seems to work - people treat her like the confident person she acts and the hottest guy in the school is all over her. It's like a dream come true, but will she be able to have the confidence to battle against all the jealous girls in her new school? And who is the creepy guy sending her love letters, who seems to know all about her shameful otaku past? Then her old nemesis Yumi pops up, threatening to expose her true identity! Will Ai be forever filled with doubt over her true self?" First volume includes a side story.