I don't know if u remember but cain was a dog in his past life, that's my theory.
I wrote that theory 2 ch ago i think,
http://www.mangago.zone/home/mangatopic/10945781/
When did they start dating? MY BRAIN CAN'T ANYMORE
They never said it out loud and Soichi is still in denial as usual but imo it happened in volume 8 when he kissed Morinaga and told him to stay by his side. Because they don't actually have a reason to be living together and having sex like this yet Soichi still wants him by his side both now and in the future.
I want to drop this since months ago and I'm still reading like an idiot bc I once thought it was cute, helppp