One good cafe meet-up and then rushing to marriage?
You come across as a desperate creep, Gonda. He also does not have much money and is physically unattractive (especially in Japan) in a way that's preventable - like wearing bad personality flaws on the sleeve instead of keeping them hidden. Cannot blame Kaori for rejecting him, even if she didn't have a kid she needs a real man who can not only take care of himself but provide stability.
Surely Gonda remembers his childhood? Poor, stressful environment. How doesn't the thought occur to him that rushing into a marriage with two dependents on a lackluster job is the recipe to recreate that horrid experience? He needs to grow up, better himself and then try again. Doesn't matter if it's with her or someone else. The reason for having 0% success in dating comes from within.
That said, setting up a meeting with her only for her to send her friend instead...oof lol. At least he got the message.