While each of these books have a self contained story, The Yakuza Path series is enjoyed best when read in series order. If you want the full scale of The Yakuza Path universe read Amy's books in this order.
Better Than Suicide
Series: The Yakuza Path, #2
Genre: Gay Yakuza Thriller
One Thousand Cranes
Series: The Yakuza Path, #3
Genre: Gay Yakuza Thriller
The Deafening Silence
Series: The Yakuza Path, #4
Genre: Gay Yakuza Thriller