A girl with lost memories and the only one who knows or knew.. where the jewel of time lays. The sister of the famous Lupin the third helped him commit a robbery, to steal the Era Gem that laid in the Kingdom of England ten years ago. Unfortunately things turned for the worst, they were both cornered and only one could escape. (Y/n) distracted them allowing her brother to run much to Lupin's dismay. However she wasn't caught that day, (Y/n) still had hold of the gem and her first idea was to hide it. Once hidden she went to go hunt down her brother, though during her travels an incident happened leading for her to lose her memories. She was caught and prisoned shortly after. Not remembering her crimes she sat confused for 6 years within the prison. Lupin having heard a rumor of his sister's location went and broke into one of the world's most dangerous and hardest to break in prison taking the risk of him being captured himself. He found her.. only to find out she had lost her memories. Lupin distressed with this issue tried helping her regain her memories while Jigen gives her new memories to remember as well as helping Lupin regain her old ones. As well trying to find the gem she hid. Jigen x Reader Note: I do not own Lupin the 3rd or you, I only the story plot for this story