I'm going to be selfish. I wish the ending was a little more conclusive, but I guess that's how it goes for an '09 manga.
I really disliked his friends and even some of the Sakurai chapters despite her being a cute character. I wanted more interactions between the two sisters, mostly the younger one but I can understand that her whole reason to exist was to wake the MC up to his feelings.
Overall, it was a nice read. I don't think I can judge it too harshly because it is clearly a product of its time. Thank god modern romance stories don't pull this "they got together, trust me bro" endings as much as they used to back then.