Lost Lad London (2019)

Blurb:
The whole of London is shocked when the mayor is found dead on an Underground train, but perhaps none more than university student Al Adley. Though he took the Tube at the time of the fatal stabbing, he doesn’t remember seeing anything unusual – certainly nothing to explain how a bloody knife found its way into his pocket that night. However, in spite of this damning evidence, Detective Ellis believes Al’s claims of innocence. Now the two must work together to conceal Al’s involvement and clear his name in the face of shadowy forces working to see Al take the fall for a crime he didn’t commit …

Source: www.anisearch.com/manga/70705