This is a hack to the (U) version of Rhythm Heaven which only replaces the English songs with their original Japanese versions. Only the 5 or so dubbed songs are affected, everything else (voice clips, sounds, etc.) remain in English, so there are no timing issues with this patch unlike other patches which simply do an SDAT swap to replace all sounds, resulting in sync issues with some games.
PPF available here: Download
(Apply using PPF-O-Matic)
PPF available here: Download
(Apply using PPF-O-Matic)