Another Time Another Leaf -Kagami no Naka no Tantei-

The game is about a girl named Sakurane Kaede who finds a lookalike of herself inside a mirror her late mother gave her. Ageha has the power to travel into the near past, where she can investigate events and talk to people but cannot touch anything or bring it to the future with her. Kaede and Ageha use these powers to investigate the mysteries surrounding them. [edited from TehVidya]

Kaede is entrusted with a little box when her mother died. Opening it, she found a mirror within it, which housed her doppleganger Akeha. While Kaede is quiet and serious, Akeha is completely different, how you control these two characters during your investigations is vital to your solving the case. When strange things start happening at school, Kaede and Akeha are spurred into action, while Akeha can go back to the past to gather information, Kaede, with her serious attitude and eye for detail, visit crime scenes and talk to related people to collect clues.