Becuse it really funny and romatic the way the story goes it normal not so rush no not so slow. The ending is pretty good too the main people in the movies are good too I hope you want to watch it ^^
and well, toradora isn't a normal high school love story, like a lot of others are, and they (the producers, etc...) know exactly when to show where the love is, and it's also has great characters that understand each other. they don't rush love like other animes either, and the love in the anime seems like online 1000 ppl in the world could get it. It's got that mature atmosphere with teenage characters
another reason is, even though it's embarrassing to say, i cried 2-4 times and felt like crying 4-6 times in the anime...