It's not really about the relationship with the OC. That said, I find Tenma somewhat OOC in this. I can't see him sleeping with a random woman. Nor would I imagine him being that...bitter internally, even after everything he went through. He seemed more solemn and sad rather than outright cynical in canon. Well-written, but ultimately YMMV.
Angewomon's review
It's not really about the relationship with the OC. That said, I find Tenma somewhat OOC in this. I can't see him sleeping with a random woman. Nor would I imagine him being that...bitter internally, even after everything he went through. He seemed more solemn and sad rather than outright cynical in canon. Well-written, but ultimately YMMV.