Loved the series, I marathoned it in 3-4 days.
I liked the art a lot, it shows all the work the artist put into it. My only gripe was the design of Asou; an Iori look-alike feels just lazy for a character that had more depth and backstory than the original.
The plot had many twists, some predictable and some surprising. The clichés didn't bother me that much, I know I should expect them in this genre. Still, the clichés and the ecchi were much better than in other series of the time, like Love Hina. The pacing was good and I think the author really made an effort to not let any threads hanging in the main story, his use of chekhov's gun was really well done.
I liked most of the cast, with the exception of Iori. 90% of the time we see her through Seto's eyes, and he never quite solves this issue of having an ideal image of her. She starts showing some personality only half way through the story, but still she seems kinda shallow to me. She loved Seto during their 3 years of high school but she never explained why she slapped him or why she was always so passive. I don't think it can be all explained with a simple "I thought you hated me" when it is clear that Seto is trying to be nice to her, he's just really clumsy. But of course, that was probably a narrative convenience. Ironically, by 1/4 of the series I just wanted Itsuki to disappear but then in the last third I just wanted her to come back and steal Seto from Iori. I almost cheer for Izumi, but Asou kinda stole the show.
The only aspect that always bugged me about Seto was that every time he got to be alone with Iori he just wanted to jump right into sex... I think they only kissed like 3 times during the entire series or something? I mean, being a dude, I know one can get pretty horny, but starting from fondling seems incredibly disrespectful to the person you love, especially if your relationship is not that deep yet... Having said that, his pervert dreams were really crazy but not too far from what one might dream as a teenager, haha. That was always welcome :D
The ending sure seems forced, there were some things left unexplained, like Iori's gift, the truth about the missing letters which is never revealed to her, Seto revealing his most pervert side to Iori (I mean, the whole peeping and dreaming that she never knew of), what Seto really wants to do in his life... also we never really get to see (nor is it explained) how they solve their "amatory issues", for lack of a better term. I think that was important because, ecchi scenes aside, Seto always seemed to get along better with the other girls in this sense. Sadly, it was all handwaved with a lame "You've caught your dream." Despite my gripes, it was one hell of a ride. Most of the cast had believable development and the plot pacing was adequate, so the end really was a letdown. I was so invested in the characters that I felt kinda empty with the ending :C The journey was good though.
8/10
Might read it again, but only the first volumes when the story had more Itsuki and therefore, more comedy.