I would not be shocked if the entire point of the first chapter was actually a subtle adoption hand off under the guise of “marriage”. Father springs this new mom on him with no ceremony, no wedding, not even a proper introduction, immediately gives an excuse to leave his child stranded with a complete fucking stranger at a restaurant, no accommodations, no discussion of house dynamics or where her room should be, doesn’t bother telling him to call after she’s settled in, didn’t kiss her or anything before immediately leaving without a hint of remorse.
And the most damning part? Saki in the middle of this interaction doesn’t do anything other than grab Jun’s hand & force a wave goodbye, telling him to say it now so he won’t regret it later, why would he regret it? It’s not like his father is never coming back right? He’ll still be able to contact him for things right? Why is this being treated like a final farewell?
I don’t think it’s a coincidence that saki just so happened to get married to a man who clearly still grieves for his late wife so much that he literally ignores his son to sit in front of it and drink, some random woman he’s known for a year or two max suddenly enchants him enough to get out of his stupor and marry her, but then he immediately ditches his newly wed wife and child for work reasons?
He wanted out, she was more than willing to give him one with very little strings attached, I doubt jun will ever see his father again unless the plot demands it or he goes looking for him