RGB Adventure: Due to some circumstances in the production company, the show was unable to continue production and had to be terminated at the 6th episode.
Manabi Straight!: The grafitti of the school in the opening scene drew complains which was later changed in mid-production.
Tenpou Ibun Ayakashi Ayashi: It was originally assumed to be aired for a year but the production team cut it in half.
Code Geass: Delays in productions and the insertion of recap episode resulted in the 3 months postponement of the broadcast of the final two episodes.
Tengen Toppa Gurren Lagann: A director resigns from the board due to comments about fans on 2ch that he posted on his Mixi diary. The sexy stuffs that was supposed to be aired was replaced by a recap scene instead.
Kissdum: Due to internal disagreement, the director left the project but later return as the general manager. The breakdown in production let to the fourth episode being a recap episode.
Darker Than Black: The production manager ran away with the manuscript.
Gigantic Formula: Character designer Yabuno Kouji abandoned his duties even before the completion of the first episode.
Lucky Star: The director was changed after being broadcasted halfway. There was also a huge stir amongst the devotees with regards to the how Washimiya shrine was depicted in the show.
Idol Master Xenoglossia: Broadcast was suddenly terminated on Tokai TV. But it later resumed on Chukyou TV.
Shinkyoku Soukai Polyphonica: After the sudden death of the show’s chief director, the show quality deteriorated.
Hayate no Gotoku!: Hayate seiyuu was hospitalised and the show broadcast order had to be changed.
Robi to Kerobi: Tsuji Nozimi’s pregnancy resulted in a change to another seiyuu after episode 16.
Bokurano: The director openly announced his dislike for the original manga which then caused a huge backlash by fans.
Sola: Chiba TV mistakenly broadcasted episode 4 at the wrong resolution size.
Nantsuiro Drops: Items in the Wikipedia article was reportedly altered by someone from the Japanese Ministry of Health, Labor and Welfare.
Seto no Hanayome: Episode 17 was cancelled on AT-X due to copyright issues.
Moetan: Episode three was replaced by episode six, which was still deemed unfit for broadcast. Ultimately it became a recap episode.
Kekkaishi: Poor ratings results in a shift in the broadcast schedule.
Touka Gettan: Asashi decided to postpone episode 25 to be censored before airing it the following week along with episode 26.
Romeo x Juliet: The singer for the 1st ending theme was arrested for causing bodily harm to someone else.
School Days: Need I say more? A crazy bitch axed her father and the final episode was canceled.
Higurashi no Naku Koro ni Kai: Same reason as School Days.
Manabi Straight!: The grafitti of the school in the opening scene drew complains which was later changed in mid-production.
Tenpou Ibun Ayakashi Ayashi: It was originally assumed to be aired for a year but the production team cut it in half.
Code Geass: Delays in productions and the insertion of recap episode resulted in the 3 months postponement of the broadcast of the final two episodes.
Tengen Toppa Gurren Lagann: A director resigns from the board due to comments about fans on 2ch that he posted on his Mixi diary. The sexy stuffs that was supposed to be aired was replaced by a recap scene instead.
Kissdum: Due to internal disagreement, the director left the project but later return as the general manager. The breakdown in production let to the fourth episode being a recap episode.
Darker Than Black: The production manager ran away with the manuscript.
Gigantic Formula: Character designer Yabuno Kouji abandoned his duties even before the completion of the first episode.
Lucky Star: The director was changed after being broadcasted halfway. There was also a huge stir amongst the devotees with regards to the how Washimiya shrine was depicted in the show.
Idol Master Xenoglossia: Broadcast was suddenly terminated on Tokai TV. But it later resumed on Chukyou TV.
Shinkyoku Soukai Polyphonica: After the sudden death of the show’s chief director, the show quality deteriorated.
Hayate no Gotoku!: Hayate seiyuu was hospitalised and the show broadcast order had to be changed.
Robi to Kerobi: Tsuji Nozimi’s pregnancy resulted in a change to another seiyuu after episode 16.
Bokurano: The director openly announced his dislike for the original manga which then caused a huge backlash by fans.
Sola: Chiba TV mistakenly broadcasted episode 4 at the wrong resolution size.
Nantsuiro Drops: Items in the Wikipedia article was reportedly altered by someone from the Japanese Ministry of Health, Labor and Welfare.
Seto no Hanayome: Episode 17 was cancelled on AT-X due to copyright issues.
Moetan: Episode three was replaced by episode six, which was still deemed unfit for broadcast. Ultimately it became a recap episode.
Kekkaishi: Poor ratings results in a shift in the broadcast schedule.
Touka Gettan: Asashi decided to postpone episode 25 to be censored before airing it the following week along with episode 26.
Romeo x Juliet: The singer for the 1st ending theme was arrested for causing bodily harm to someone else.
School Days: Need I say more? A crazy bitch axed her father and the final episode was canceled.
Higurashi no Naku Koro ni Kai: Same reason as School Days.
Source: MoonPhase, Alafista
