I have no idea how old they are as Avex have not stated on their website the years they were born in, but i found a fansite dedicated to them, Style. When i first watched Kirari, before i did any research, i thought they were like 16 - 20 when the video startedbefore i saw their faces, but when i saw their faces properly, i thought "they can't be no more than 13 yrs old." and yep, i was right. the oldest is 13, youngest just turned 12.
They have some good singers (only two at the moment as only two of them had solo lines in both songs) and an amazing dancer (don't know her name but she has the solo in the second PV.)
They sort of have this AKB48/Hello! Project feel to them. Their ages reflect H!P what with the training starting from 9/10 yrs old but their look is more AKB.
~could be sisters~
So far, their debut went in at number 22 on the oricon daily chart and was number 30 in the weekly chart.
So comparing their Debut to S/mileage and Momoiro Clover, I'd say even tho i like Kirari, It's not as good as Momoiro Clover's who but the way, released their Debut on the same day and reached number 1 in the Daily and Number 3 in the Weekly and from what i know are still at number 3. With the way H!P songs are placing, (please don't hate me for this) but i don't think S/mileage will do as good as Momoclo. Hopefully they'll get a top ten place (I've pre-ordered my copy already).
I'm looking forward to hearing more about thes girls but from what was said over at H!O, i don't think they'll last long with Avex.