Unlike many other shoujo mangas, Last Game establishes a firm foundation for the relationship between the lead characters. I think this is the primary reason it has a "very high" re-read value for me, since the shoujo genre is littered with love-at-first sight pairings and weakly defined character traits. Yanagi and Kujou have definite strengths and definite flaws, and both sets are continuously acknowledged throughout the series.
However, Last Game is also VERY satisfactory when it comes to your standard shoujo expectations. There are touching romantic moments and substantial character development in several subplots. But be warned: about twenty chapters elapse with relatively no progress in the main storyline. I only noticed this during a re-read of the series, and it shocked me. I took my overall rating down from a 9 to an 8. Around chapter 20, Kujou has a key realization, but she fails to truly act on that realization for, as I said, the next ~20 chapters. The heck?! So I would encourage new readers to either get comfortable before settling in for the long haul, or to otherwise (dare I suggest it?) skip a few chapters here and there to maintain interest.
However, I would still encourage you to read the series due to its well-executed conclusion and for some refreshing perspectives on common shoujo types. Yanagi serves as the primary narrator, and his arrogant overtures and honest devotion to Kujou is so unlike the tepid and twiddling thought processes of your basic shoujo female narrator. Kujou is also refreshingly capable in every facet, except for communication, and this is what causes the 20-chapter lag since the focus shifts to her. I suppose I'm essentially stating that you should read this series for Yanagi, whose personality/disposition is usually allocated to a side character by most mangakas. And as I stated at the beginning of this review, Last Game succeeds in establishing legitimate grounds for a relationship between the main characters: common interests, extended time spent together, genuine appreciation for strong qualities...
It's a good read. You should get some real laughs out of it.