Shugo Chara! Vol 3

From the Kodansha edition

CAN A BAD GUY TURN GOOD? Amu’s Guardian Characters have been stolen by her teacher, a bitter man whose dreams died when his own egg was smashed. When Amu goes to reclaim her Characters, the School Guardians are there to help. But can they get Amu’s eggs back and put the evil teacher’s egg together again? This volume of Shugo Chara! includes special extras after the story!

Source: Anime News Network Encyclopedia