Hadn't noticed until you mentioned... the characters are really similar, but their situation is very different, in this one the blond at least had a reason to be weird about approaching him because he thought he had a child and was recently divorced, in TTE the guy was a jerk for no reason lol
There's the whole having a constant dream about rejecting him in high school, the exact personalities + matching characters design (minus the blonde hair instead of light brown), and the exact same "third ending" where they finally end up together. The blonde character even mentioned it himself (something like "are you gonna reject me a third time").
Regarding the plot, the blonde guy approaches him just to be able to reject him and move on. Gets rejected, realizes he's in love. Begs for a 2nd chance. Hence the happy third ending.
This is entirely my opinion of course, but I dont think adding two kids into the plot completely differentiates it.
(Didn't mean to write an essay. my bad)
I've actually been thinking that since I started reading it!
I'm surprised no one has mentioned how many things it has in common with "The Third Ending".