True, with regard to Mishima’s timely (?) demise. Poor judgment (based almost certainly on sentimentality) fouled the clarity he was trying to achieve, and I think that lends some weight to the necessity to make sure one is thinking “above the head” as it were, that state of mind wherein one makes the perfect chess move and isn’t consciously certain why.

As to leaving a mess for someone else, I think that will be unavoidable in the sense that you’re rather forcibly breaking others’ attachment to oneself, through an act with an certain taboo attached to it. In that sense there’s a karmic “stain” left behind, which isn’t the ideal, and perhaps it’s that “stain” that we’re still dealing with, with regard to the death of Jesus and the rise of his numerous purported followers, some of more or less demonic constitution, who are legion.

My damned individualistic idealism prompts me to look at taking oneself out on one’s own terms as a sort of large-scale version of quantum fluctuation, where one’s death corrects the temporary energetic imbalance created by one’s birth, without leaving a trace behind and without thereby disrupting the equilibrium of the universe… but then my blessed cynicism comes in and points out that one can’t disrupt the universal equilibrium – because it is a dance, according to Newton’s third law of motion (to every action let there be an equal and opposite reaction).

So yes, as long as one made a difference during one’s life there will always be a mess to clean up, which is the catch-22 of the “perfect death.” Hopefully, however, one’s closest friends and family would be well-enough acquainted with one’s thinking and essence to know that consciously dying is just as much a cause for joy as it is for sadness.