It takes place during the Showa Era in Japan. The story revolves around a young man who has lost both his mother and father. Now, the only person he has that he can rely on is his butler who has been working for the family. However, his father had a secret he was hiding. This secret reveals itself after his demise.
Related: Psychedelics (Ch 11-15)
http://www.mangago.me/read-manga/tourou_no_ori/
Tourou No Ori