I'm guessing time treated someone very well.

That feeling when the little girl you parted ways with during high school graduation, turned out to be quite a catch when you met her again at your batch's reunion.

If only boys in manga/anime had better foresight...

Its pretty much guaranteed that most of the girls they bullied or joked around with in their younger days would grow to be such beauties.

meganeshounen said:

That feeling when the little girl you parted ways with during high school graduation, turned out to be quite a catch when you met her again at your batch's reunion.

And that feeling when she still wants you.

I think the full kanji of the bottom sign is 第47回卒業証書授与式 Dai-47-kai Sotsugyō-Shōsho Juyoshiki "(... Middle School's) 47th Graduation Ceremony”, the "47" playing on this being Tawawa on Monday #47. This means that the middle school in question was establish c.1964.

meganeshounen said:

That feeling when the little girl you parted ways with during high school graduation, turned out to be quite a catch when you met her again at your batch's reunion.

Middle school, according to the sign at the top-right.