Why was Yamakan replaced by Takemoto as director of Lucky Star?

Question

When Lucky Star began airing, the show's director was Yamamoto Yutaka ("Yamakan", as he is often referred to). However, after 4 episodes, he was taken off the project and replaced by Takemoto Yasuhiro (one of Kyoto Animation's longer-time directors), who went on to direct the remainder of the show.

What happened? This is the only time in KyoAni's history (since they started being a main production studio in 2003, anyway) that a show's director has been changed midway. Kind of weird, huh?

I'm aware of the general belief - that Yamakan's direction of the first four episodes was so bad that they had no choice but to get rid of him - but I'm looking for specifics, preferably from the mouths of the people involved.

Answer 1

The official reason given has been a very vague "He has not yet reached a level required of a director."

「らき☆すた」監督の山本寛は、監督において、まだ、その域に達していない

Because of that, people assume because the 4 episodes he produced for Lucky Star were of such poor quality, he was sacked. That said, no one else has been fired from KyoAni or AniDo in this manner ever since, so the situation left many puzzled.

Shortly after his firing, people speculated he was fired for sexual harassment instead, especially after an anonymous person claiming to be staff posted that he had stalked her several times. Nothing was directly confirmed, but his behavior after getting fired didn't help in this either. During production for Wake Up, Girls!, he harassed the female seiyuu (who were of high-school age at the time) to the point she had to tell him to cut it out. He's also criticized the #MeToo movement, claiming he would proudly continue to tease/harass women.

Just recently, an anime adaption of a light novel got canceled for racism against Chinese being prominent in the story. Yamakan complained it was the end of anime and stated in his blog that he also has racist views.

Generally, bad director or not, he's consistently proven himself to not be a good person, and it's highly likely that him "not being ready to be a director" was just the nicest way KyoAni could put it as their reason for firing him.

Answer 2

Here's an official press release about him being replaced from KyoAni. The reason for it is described in it as follows (emphasis mine):

[...] 「らき☆すた」監督の山本寛は、監督において、まだ、その域に達していない [...]

It's hard to translate this since it's in (probably intentionally) vague words, but it says something along the lines of "he has not yet reached a level required of a director."

The phrase (in bold) used to condemn him is well known among fans. Yamamoto himself often quoted the phrase in his works, including Kannagi.