thank you!!!!! ok.. doumeki is a bit scary in the end.. but whatever..
Thank you!!! Thank you!!!! Thank you!!!!
When you look at the panels, what you see suggests these are Yashiro's thoughts, but I think the same as doumekichikara, who translated these 6 pages, that these are the thoughts of Yashiro or both of them (Yashiro and Doumeki).
More on this opening monologue: http://doumekichikara.tumblr.com/post/125623233402/breaking-down-the-internal-monologue-since-it-is
Going by what you see in the panels alone, it could really go either way.
However, I still think these are the thoughts of Doumeki because of one thing: He mentions that he is a person without inhibitions, and that he only became aware of this when he held him down. Yashiro, as we all know, is certainly a person without inhibitions, but he has been that way for years upon years. There's no way he could have realized that just in the last chapter.
In my mind, it make way more sense for Doumeki to be realizing these three things about himself than Yashiro.
First 6 page translation
http://lustfulcat.tumblr.com/post/125572814550/i-will-do-everything-that-must-be-done-who-is