kunimasa has always been an awkward kid. i noticed that. i think makio mentioned this before.
and yeah, i agree with you. he probably decided to let go as to preserve that innocence. kunimasa figured that norio had no idea what it means when he says "yes". kunimasa knew very well the heavy burden of his responsibility as the next head of their fucked-up clan. so now that he does not see norio as a tool but as someone he cherishes, he does not desire to let norio to delve on deep in this darkness.
So what I got from that last chapter was Kunimasa let Norio go because he loves him yet he feels like Norio is just going with the flow because of Kunimasa's responsibilities. I think Kunimasa thinks Norio is so innocent that he doesn't understand the responsibility and confusing love, like Norio doesn't really love him because he's naive? Am I close or what because I'm so confused?