Why do they say Kakashi's name like this in Japanese

[lukerules_96]

When they say Kakashi Sensei they say something like kaku-sensei. I wonder why

[雏田hinata]

sensei is teacher right?

i guess its like sasuke , the say it so fast you only hear saske (you dont hear the "u")

kakashi sensei ... say it to fast and its kakasensei >.<

[Kakashi Hatake_Yamato]

yea...i hear that all the time too....
i think its kinda long to say the whole thing....kakashi-sensei, so they kinda cut short to kaka-sensei......
kinda sounds awkward...

[katsu uchiha]

I believe thats the way they pronounce it in Japan.

[ban_shi]

i thing its just like we say our words. we say things fast just like they do. no different