Missing 

He’d answered his master’s summons with his heart in his throat. Sanzo priesthood was a burden he would rather refuse, but if that was what his master wanted of him, so be it.

He knelt and said he wasn’t worthy of the title. But Koumyou was undeterred, unconventional to his last breath.

“A Sanzo needs a strong body, but a strong spirit is more important still.

“It’s your turn to be strong, Priest Genjyo Sanzo.”

With those fateful words hanging in the air, his master only had time to pass him a rolled-up sutra, and he only had time to stash it inside his robe, before a youkai burst into the room and tore Koumyou’s life away while also relieving him of the sutra he bore.

Afterward, Kouryuu remained huddled and miserable even after his paralysis wore off, until Shuuei found him. He rebuffed all attempts at comfort.

He couldn’t revive his master, but he could retrieve his master’s missing sutra. That was his mission now, one he would achieve at any cost.

His entire existence since then -- including the journey west and his stint at Keiun -- amounts to nothing more than chasing the one that got away.