what does kun san chan sama niichan and niisan mean????

They are all Japanese descriptors that come after a name.

kun – often used for male students

san – default title

chan- someone who is a child or someone you have no respect for

sama- someone you have great respect for (as in very very important)

niichan and niisan – brother and sister

They are honorifics that u put at the end of japanese names. Kun and chan are the same thing. they are used for someone that’s close to u like a friend. but kun is used for a boy and chan is used for a girl I forget what san is used for.. sempi is used for someone whose a senior in high school and sama is used for someone who’s older that u aren’t friends with.