User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-26200890-20150412161939/@comment-26088683-20150412164633

you can try Baka-Tsuki, here is te link and they are english

http://www.baka-tsuki.org/project/index.php?title=High_School_DxD

Shortly, manga is like a comic book, but a LN is like a short novel.