Anmitsu Hime
 

At age 16, a tomboy princess, Princess Anmitsu, has no love interest in her life and worries her parents. Despite their concern, Anmitsu runs away from the castle to venture into the commoners' life. During her daring adventure, she befriends a group of children who make a living by pick-pocketing. At th same time, she finally meets her prince charming Senbe, the leader of the group. However, she soon finds herself in an awkward position when she learns of the children's new plot: they are planning to steal the treasures from her own castle. Will she be able to put a stop to it without revealing her true identity? -

source: http://wiki.d-addicts.com/Anmitsu_Hime