In my opinion he should have confessed earlier.
Seriously, TWO FUCKING YEARS?
If you like a girl you can't waste 2 years in visits to her workplace to half-ass flirt with her. There's no way she will take you at face value if you do that. Maybe at first, like for a few weeks, she will think that maybe you're for real; but after TWO YEARS of nothing but teasing she will be certain that you're just a joking clown.
That part at the end where he finally gets serious and confesses convincingly? Way too late, dude. Next time don't wait 2 years.
If I'm not mistaken, this is kinda epilogue for Ogino's Toumei Ningen no Hone. It's from the author so it I guess it's canon tho it was never explained what happened between the ending and this extra
i thought this took place when senpai was constantly staying over at the mc's place...because this just doesn't make sense as an epilogue