oh my god. i just found mold under my mattress pad.
japanese bedding consists of a mattress pad, futon, comforter (ie quilt) and a pillow. you're supposed to air out the mattress pad and futon whenever it's a dry, hot, sunny day, but for the two months i've lived in my apartment i haven't done it once - and i'm seriously regretting it.
i googled how to deal with moldy futons and it said that sometimes mites can grow inside! i clean my entire apartment top to bottom every week and now i just feel.. dirty.
if you need help with futon maintenance here's a good link: