Wit's manga / #time travel(2)

Coming back late form work one night, salaryman is threatened by an old fashioned looking foreigner at his door. Turns out the guy time travels back in time and is now making himself comfortable in his home

Okita's descendant, and omega, somehow goes back in time to the Edo period and is mistaken for his ancestor. He is helped by Hijikata but ends up falling for the man along the way