yup in fact there's been referd によって either takuya または j.p but i can't seem to remember it's been like 2003 that's when tgis 表示する came out and yes gamehot2 there twins if あなた listen closey to their voices you'll hear that koichi sounds older than koji but neverless they are in fact twins
but i also like saya and diva, but i like them both as individual characters and not necessarily as twins although i do think theyre relationship is really interesting and how like pretty much the whole plot in the long run revolves around it is awesome but yea, i like them もっと見る as individuals.