Secret Affairs of Earl Thatree and His Lodger

It's the early 20th century. Foreign exchange student Ichiro Yamada has come to live at a boarding house run by the handsome young aristocrat Albert Thatree. For some reason, incidents haunt them everywhere they go. They solve cases with Al's clear mind and Ichiro's ability to take action and his intuition, but these two begin to form a bond that goes beyond friendship...!? A mystery romance set in England begins!

(Source: Oakla Shuppan, translated)