http://vatoto.com/comic/_/comics/seito-kaichou-ni-chuukoku-r7889
I don't see any tag or notice indicating why there aren't chapters.
tag added; seems like the first 3-4 volumes are direct scans of the official english release, but the rest simply never got uploaded (doesn't look like scan groups for this have a policy forbidding this and it doesn't appear to be overly explicit/porn either)
http://vatoto.com/comic/_/comics/the-breaker-new-waves-r154
Chapters were there last month, but now all of them are gone.
Chapters are gone since 2013 or so. If there was anything there, then the uploader ignored the 'do not upload bcs author request' notice in the description. Plus there's the 'no chapters' tag present already.
No chapters showing up for Nisekoi
http://vatoto.com/comic/_/comics/nisekoi-r951
It has both the 'no chapters' tag and the explanation why chapters are missing...