Tensei shita Assassin wa Kenjutsu no Tensai

Writing a proper synopsis for this one isn't possible due to a lack of available information. The title, studio, genre, episode count, and original story details are all either missing or unconfirmed — and the research turned up a live-action drama rather than an anime, so there's nothing solid to go on here. Writing a synopsis without that foundation would just be making things up, which doesn't do you any favors if you're trying to decide whether to watch something. If you can track down the correct title or a MAL link, that would make it possible to give you something actually useful. In the meantime, if you're browsing for something to watch and landed here by accident, it might be worth double-checking the title spelling or searching by genre or year instead. Sometimes entries like this are placeholders for unreleased titles, mislogged records, or series that got cancelled before airing. None of those make for a great recommendation. Come back with more details and this becomes a much easier problem to solve.