I (50% Chinese, 50% Japanese) used to live in Pasadena back in the early 00's! Loved Arcadia more though as I met more Chinese and Japanese fobs there.
I have taken Japanese 1,2,3,4 at PCC. All I wanted was an easy A grade back then so I started from Japanese 1 even though Japanese 4 was no sweat for me.
Sorry I can't give you a candid answer from personal experience. I just daydreamt in Japanese 1,2,3,4 because I have learnt the material before. Most of my classmates (who were Chinese) found Japanese 4 to be challenging. With your background, I say go for Japanese 4 at PCC then!