If 당신 had to wright an essay on why 당신 want 더 많이 망가 in your school 도서관, 라이브러리

I guess some reasons would be that 망가 have japanese traditions in it, which will teach people about japanese cultures and stuff.
Also they would be popular, which would encourage people to read 더 많이 books.

Yeah, pretty much just exaggerate your points.. haha. ^_^