Akihi

Akihi Senoo is a mild-mannered and unassuming high school girl like any other. However, she is actually a talented artist and a genius art forger. When not wearing a sailor uniform, she is a highly skilled art dealer who puts the adults around her to shame. However, her goal in the art world is to find a portrait of herself, drawn by her late father.

(Source: Shogakukan, translated)

Included one-shot:
Volume 6: Ao no Kishou