Mmm, I like. The story is fairly minimal, but well written, and it's refreshing to see a guy who is both a strong dominant and a nice guy. There's some irony that the guy who finds the magic mind control book already has a pair of highly submissive girls in love with him, and it's a welcome change from the horny 18-year-old virgins who usually find those.
Also, I like the latest chapter, not having anyone new enslaved is different but it works well. There are quite a few ways to make adding new girls interesting (how about a girl with a fetish for mind control finding out about him and begging to be enslaved, for example), but being open to stories about a magic man with a harem doing things other than taking more girls opens up a lot of options.