Kizuna Deluxe Edition Vol. 2 (manga)

A small misunderstanding leads to serious trouble for Ranmaru and Kei. However, their bond is so strong that they can overcome anything! Their happy life together continues, until one day Ranmaru's grandfather and dojo master asks, "Will you choose the path of the sword once more?" At the same time, Kei spots his half-brother Kai selling drugs in shinjuku! Why would Kai do such a thing...?!