
Please explain my previous question to me. I hate it when im logged out.

They are related. They both have the same mom but different Dad. Eiki was already in love with Mairo when they were younger, and he didn't want to lose him, so he drew Mairo into this forbidden relationship. But as time grew by, Eiki doesn't want to have sex with each other anymore. He realized how wrong it was, but by then, Mairo was really in love with him, therefore he won't let Eiki go.
Wont there be a side story of the kids grown up
There is already one. It's the Ookami no Ketsuzoku....