Pokemon Mystery Dungeon: The Keepers of Time

Rose is a Riolu with a troubling past that she can't remember, other than the fact that she was a human! She meets a Shinx named Jet, and they become an exploration team named Team SteelSpark. A Treeko, named Vine, joins soon after.

Little did the Team know, Rose was on a mission of her own. She vaguely remembers she had a partner with her. And she's determined to find him again. But she doubts she will.

Until... A Time Gear gets stolen. Then another. Then another. It is after the fourth Time Gear is stolen that the Team goes out to find The Thief. But when Rose comes face-to-face with him, suddenly she realizes something startling, that every time she sees The Thief, something goes off in her mind. Like, her memory.

Then, suddenly, something terrible happens, and a Pokemon that was once a friend ends up being the real villain. Before long, Rose realizes the partner she was searching for... ended up being someone she'd had never thought was.

Cover art and chapter art isn't mine! They belong to their rightful owners!
Spoilers for the PMD: EOS game!