Gin after the previous isekai event he was been sent into a dimension where samurai's role were been erased for a really real long time ago instead there are peoples who dressed up strangely and he encounters with unique characters over there to, but the problem is that thanks to Gin's stupid he gets involved into infinite problems with the color gangs and the unique characters.

A black hole swallows up the whole Gintama cast and sends them to the Durarara universe. Everyone forgot about Edo and went on like they have lived in Ikebukuro their whole life. Except for Gin. He remembers almost everything and goes on a quest to help them regain their memories and get back to Edo. But, events prevent regaining their memories and they're get slashed one by one...