That is definitely how it should end
Nope , Ren will be much better with Rush-it's stated in the doujin that Ren was rush's master.
What yaoi bakamono said is right...
ren and kaito get together... because rush will meet someone who looks like ren, his name is surge...
I read the dj I think it was before rush was a area master and before he met ren and kaito so we'll never know ╮(￣▽￣)╭
I ship them even though rush is a dog ╮(￣▽￣)╭
Nata lives....
Ren and Kaito get together and that is how it should end...