ばか！バカ！　馬鹿ー月！

I am just wondering. Why sometime Kyon addressed Asahin with "SAN" but somtime time he didn't ? If it's just it Kyon's thought then it's fine for me but when he spoke to Asahina what happen to the "san" that he should said. In Japanese's cultures shouldn't there be "san" after their senpai's name? In chapter 6 Kyon still called Asahina as Asahina-san but when it came to chapter 7 he just call "Asahina".

Can anyone clarify me on this, thankyou.

Ah~~ So many wrong spellings and I cannot edit what I wrote.
Sorry for my poor english.

That was my mistake in the early stages of translating.

I do not own the Japanese version, and as the Chinese language do not have such suffices, I have to guess which characters use what suffices (-san, -chan, -kun, etc) for different people.

At first from the Chinese text, I surmised Kyon to call Mikuru "Asahina-san" when speaking to her directly, and simply "Asahina" when in narration. It wasn't till watching the anime that Kyon calls her "Asahina-san" all the time, as seen in my more recent translations.

The same for Haruhi calling Koizumi "Koizumi-kun" and Yuki "Yuki".

The usage of `san` or `kun' , or without them shows the speaker's attitudes to his/her friend. That is, when adding 'san' to a girl, or adding 'kun' to a boy, the speaker is a little bit more polite than without using them. When calling his/her friend without 'kun', 'san', he/she has more friendly attitude. Calling his/her friend's name without 'kun' or 'san' is sometimes boysh usage.