Will the manga and anime industry still be there after 100 years?

yes manga is just Japanese for comic and anime is just a specific style of animation/cartooning that some artists prefer over other types of of art, Because of that comics and manga will always exist as a form of expression long into the future. However I predict that in the coming decades it popularity will diminish and independent comics will become more popular as fan bases age since there is less censorship and more mature story lines available.

will be human still be there after 100 years.

No, people will begin to realize how childish anime and manga is. Anime is for virgins that dwell in their parents basements well into their 30's. No self respecting responsible person watches anime once they're an adult.