There’s no Sagiri or Gabimaru in this episode. It’s given over entirely to the duo of Tenza and Nurugai, the island’s cutest couple. Tenza came from nothing, was nothing, but was taken in by a member of the Yamada Asaemon clan who believed he had potential.
Now he himself is a Yamada Asaemon, and like his master, has decided that simply executing someone of Nurugai’s potential (both as a person and a wife) would be a waste. Unfortunately, on this island, both of them draw breath at the pleasure of the Tensen.
When then Tensen attacks, Tenza is thrown back and disabled, but before the Tensen can attack Nurugai, he finds his second wind, lops off both the head and hands of his opponent, and flees through the forest with Nurugai. When the quickly regenerated Tensen instantly catches up with them, they’re both saved by Tenza’s master, Shion, a blind mad with a kind heart.
When Shion points his sword at Nurugai and asks why Tenza hasn’t executed her, Tenza shows how much he’s grown by speaking like a man, insisting to Shion that he’s only doing the same thing Shion did with him. Not only does he see potential in Nurugai like Shion saw in him, but she is that something Shion told him he’d come to want to protect.
But while Shion tables the question of Nurugai’s fate for another time, all their time grows short as long as the Tensen persues them. It cuts Shion’s throat, and Tenza digs deep into his swordsmanship to simply buy time for his master and Nurugai.
There was a time when Tenza didn’t believe in his potential like Shion did, and had decided to quit his training. Shion agreed to let him go if he could land a single strike on him.
When fellow Yamada executioner Eizen showed Tenza the grave of Shion’s former student who had fled and become a criminal Shion himself had to execute, it motivated him to not only land that strike on his master, but decide that he wanted to stay and continue to be taught rather than run away.
In the present, Tenza doesn’t run away, but fully realizes the potential Shion believed he had by sacrificing himself to allow his master and Nurugai to escape. Nurugai is beside herself and wants to go back to where Tenza is, but Shion insists that’s not what Tenza would want.
It’s clear that no human, no matter how skilled, is a match for a Tensen. It’s also clear that Jigokuraku is not above teasing enticing executioner-prisoner ships and then promptly sinking them with extreme prejudice. Tenza’s past was efficiently and compellingly laid out this week, and his death is a cruel gut punch.