Responses
Yeah. I get that he said, tell me to stop and say no if it is too much, but usually saying no and saying stop are BIG parts of making BDSM more realistic and thus are ignored because it is just another part of the play. Thus the need for actually safe words, so the dom KNOWS that the other seriously means STOP.
I am quite surprised Shizuru talked it out that much with Akihisa, I did not expect that. Having discussed that Akihisa can leave the room if he cannot handle anything anymore is enough as safe word for me. "He's tied up blah blah blah" yeah I know but if he says, "I want to leave the room" while tied up, that is considered valid as much, at least that's what I understood from Shizuru.
BUT that hanging thing though. Like SHUT IT, that's just impossible. No back support at all. The weight is concentrated on Akihisa's neck and back, legs and arms need to pull each other, which will ridiculously hurt, if he relaxes, he wouldn't be able to sustain that position.