The Actual Ending

At the end, Aqua successfully kills his mother's murderer and survives. After that they both, that is., Aqua and Ruby lives their life peacefully for few months, but after that Aqua starts to notice that he is romantically getting attracted to Ruby, he tries to ignore it but can't, one day at night Aqua slips into the Ruby's bed and hug her tightly from the back, Ruby startles but then asks what's the matter, then Aqua asks was she serious when she was saying "She hadn't forgot their promise of marrying at 16", then he explains that he's getting attracted with Ruby too much, he tries to resist or ignore it but cannot, he wants to know what does Ruby wants as he was there for her before in the hospital too and will be here too no matter what, if Ruby wouldn't clarifies it now, his feelings will grow stronger and stronger and it'll be impossible for him to stop then, if Ruby wants to remain like they already are, he won't have any problem but it could be difficult later. He says all this while hugging tightly Ruby on her bed from behind, Ruby listens all this and notices Aqua is sexually aroused, she slowly turns back and kisses Aqua for 2 minutes, then says I was always serious Sensei, Aqua says he's so relieved, he's the happiest person in the world right now.