If they do officially release the light novels in English...
I hope they give each volume different titles. The full title only works for the first volume after all, and even "The Second Prettiest Girl In My Class" isn't accurate for every volume. Though I'm aware this will never happen because the original author didn't title them differently. (I'd still keep the volume number for reading order, like how Haruhi and Rascal does them.)
How I'd title them is something like this (and I hope they don't spoil too heavily)
- I Made Friends with The Second Prettiest Girl in My Class
- I Fell in Love with The Second Prettiest Girl in My Class
- New Year and Valentine's with The Second Prettiest Girl in My Class
- The Second Prettiest Girl in My Class: Second Year, Different Class!
- The Second Prettiest Girl in My Class: Vacation and Summer Break with Her
- The Second Prettiest Girl in My Class: September Sports Festival!
- The Second Prettiest Girl in My Class: But What About the First Prettiest?
- The Second Prettiest Girl in My Class: One Year On!
- The Second Prettiest Girl in My Class: Third Year, Same Class Again!
- The Second Prettiest Girl in My Class: What the Future Holds for Us
(Extra Volume 7.5, if it gets translated, would be titled something like "The Second Prettiest Girl in My Class: From Their Perspective")
P.S. I'm aware they're already translating the manga but that takes three volumes to cover one LN volume.