When Mori found a four year old mer caught in his net and decided to put it through the mer domestication program, later taking in said mer and naming him Osamu - Mori knew that he would have to learn knew things and make compromises where he hasn't before. Still, he loves Osamu very much, like he's his own flesh and blood! That's his baby boy right there, and he would do anything to keep him safe.
Mori quickly got used to caring for a mer. It honestly wasn't as difficult as people made it out to be. Mers require somewhat different needs than a human, but once you learn to accommodate, it was a piece of cake. Today, though...? Yeah, Mori was NOT prepared to find this out about merfolk.
Osamu has been having issues with his teeth lately. After a few days of it not going away, Mori scheduled a dentist appointment for the fifteen year old. After a quick check, the dentist - who is used to helping mers too - identified what was wrong.
Mers don't have wisdom teeth, but they do have something similar that grows in which can be painful. Once bad enough, the mer's instincts will kick in and they'll rip out the bad teeth themselves. For.. obvious reasons, they don't want that to happen. So, Osamu was going to get them removed today.
Everything went well, of course, and now Mori is taking a drugged up mer home with him - still high on whatever meds they gave him for the pain. Looks like Mori will be taking the next day or so off of work to care for the boy.
Mori carries Osamu to the car and lies him in the backseat, checking to make sure the sponges are still taped in place over his gills so he can breathe. Due to the operation needing to be done to Dazai's mer teeth, he had to transform to get then removed, and now that they also need to heal, he'll be reduced to mer form for a few days.
"Hey, baby." Mori coos, ruffling Osamu's hair before closing the door and getting into the drivers seat. "How are you feeling, bud? Anything I can get you? Maybe some icecream on the way home?" He suggests as he starts the car.