Hi everyone.
I'm new to the forum, but I'd be grateful to anyone if you could help find out a specific Manga That is driving me crazy.
It's a manga from about 10 to 8 years ago, I think 2011 but I'm not sure.
Its release was a little bit troubled, I remember chapters were released veeery slowly.
I can clearly remember that there was a chapter n. 1.5 between 1 and 2.
It was about time travel: there was the protagonist, a thin blonde boy (usually dressed in black with a hat) and he travelled back in time as a job.
Chapter 1 and 1.5 were about him going back in time, and searching (and maybe even trying to stop, I don't clearly remember) Jack the Ripper.
I don't really know why I am so bounded to this Manga, but I'd really appreciate help.
Thanks everyone in advance for your help.

Toki no Shoushitsu Ukeoinin?

OH MY GOD THANK YOU, it's him!
You saved my sanity 🤣