Gokudo Girl

Pretty little Mai Hyodo is a high school freshman who just couldn't look any cuter in her high school "sailor" uniform. But Mai's dream is to restore the Kanto Hyodo Gang, a crime family headed by her late father. And with Tetsu, her father's ex-lieutenant, she's "doing what it takes" to restore the organization to its former standing.

(Source: MangaUpdates)