create alias pretty_rhythm -> pretty_(series)
create implication pripara -> pretty_(series)
create implication idol_time_pripara -> pretty_(series)
create implication kiratto_pri_chan -> pretty_(series)
Reason: Kiratto Pri Chan came out recently, the recent addition of the Pretty series. Since it doesn't have a tag yet (only for Pretty Rhythm itself), I think it's high time to merge them together.