A crucial twist amid the battle between Mayuri and Pernida, Nemu risks her life to save his master/creator but she earns his ire instead.
While the reaction of Mayuri is predictable considering how he has always treated her, what he said seemed to open a whole new avenue of implications.
"Nemu Nanagou, I'm sure you realize how much of a burden it would be for me to raise the 'next you' in the same way as the 'current you.'"
"If you do not know, then refrain from acting on your own intuition and instincts. You do not have the freedom to sacrifice your life as you see fit, your life will only end when and where I deem appropriate."
The caption also read "The secret has finally been revealed."
"Nanagou" is translated as "mkVII" or the "seventh" implying that Nemu is probably the seventh clone. The question is-a clone of whom?
Reddit user "ShishouMatt" called it: "I am calling it now that Mayuri either had a love interest or a child that died because they didn't listen to him. So he made a new one that would obey."
That would add more depth to Nemu's character and also a glimpse of Mayuri's past-and probably the key to his madness. It would also be significant because it would be the first time that Mayuri would show any form of emotion.
Other theories debunk the emotional connection and have more practical themes-that Nemu is a prototype or a special weapon-something that Mayuri took seven versions to perfect-and that makes her valuable.
There are a lot of things to look forward to on Chapter 641. As the big secret will be revealed, there is also a furious battle raging. One interesting development is that Pernida seems to be evolving himself-and Mayuri may have run out of weapons. Will Nemu be his trump card?