Coz I don't know if I'll be able to do justice to this idea at the moment, I'll share this one. Yusuke is transported to another dimension/timeline/universe & the only way he can get out/escape/get back to his world is with the help of Keiko. But in this world, Keiko is the Spirit Detective & the one with the Spirit Gun. How do they both get him back to his world and how will they both deal with the differences? Bonus angst: Her Yusuke is dead. Bonus: She was working on a case when he drops in.