Adaptation Displacement: Many fans read the manga adaptation first. Some did not know that the series is primarily Light Novels and that only half of the first volume (arguably the best story) was adapted into manga, leading to complaints that they cannot find volumes 2 and 3 of the manga, which never exist.
Counterpart Comparison: Yuichi and Asaka. It is lampshaded in the third novel that the reason that Wataru likes Asaka because he unconsciously reminds him of Yuichi in his Honor Student Mode.
Marty Stu: Yuichi is a borderline case, what with having looks good enough to be compared with models, being both intelligent and athletic, and "nice to everyone he meets" (except one, guess who?). His insecurities and his childish picking on the boy he likes arguably make him more human (and believable).
Vaporware: the English translation of vol. 5 was slated to be released around June 2010, but there is no sign of it half a year later. Averted for German version, as all five volumes have already been published.