There are no MVs in SIF, though, if you meant SIFAS then just click the "Video" button under the song. Only songs under the "Normal" Category have MVs, though there are some songs that don't have a MV.
There are no MVs in the school Idol festival mobile game. When it comes to games, MVs are only in the mobile game School Idol Festival all stars, the arcade game that was recently released on playstation School Idol festival After school activity and in the 3 sub unit themed ps vita games.