Nothing you can do but repeat it over and over again, because Japanese speak fast and Chinese are known to speak slow

My method: watch your favorite Japanese drama or variety show and read along with it, especially the variety show, which has subtitles, and learn the intonation by following the subtitles, for both men and women

Also, find fast songs and sing along with them, and memorize the lyrics (I use the song "GREEEEEN FUNKY MONKY" and "BABYS QUAMINGO"). BABYS, the cassia song. Once you know the song, you'll be able to speak well.