That was a rather sad chapter... When Kaneki ran to Arima and cried, I already knew this chapter would get me emotional. :(
But wow...Arima was a half-human. He ate normally and did not have a kagune, but he just had better physical abilities and had a shorter lifespan... The Washuus are ghouls all along.
Arima looked like he was so at peace when that flashback of a younger Arima letting a butterfly go, flew away... Arima is finally free. :)
I look forward to seeing what happens when people hear that Kaneki murdered Arima.
I'm so glad lots of information was told this chapter.