That's not a cliche but the climate, I think. (How do I say it? For them, It's cold, but for us, It's normal?) When I visited Japan in winter(at its coldest) It was DAMN HOT like a summer and people did actually wore thick coats and scarfs, hats. .etc When I walked with a single t-shirt, Japanese ppl were so shocked and kept asking me if I weren't cold and when I said it was like summer outside, they were astounded. And even when we were in house (which is perfectly warm and cozy) they kept wearing their coats, saying It's soo cold and used heater. Also they use super super super super thick blanket that could stand like -10000 celsius :') So I think they do catch cold if drenched in rain. Also, taking bath or taking shower at a stranger's house is so stereotype and cliche in mangas as if they're some kind of neat-freaks (Sorry if I offended someone here) But I, myself, took a shower at a stranger's house, tho. .The funny thing is that everything was prepared. lol. Extra towels, extra slippers. . :'D And they take shower twice a day, which was so new to me. Because in here, it reaches up to -40 to +30 with a very dry air that taking a bath everyday, let alone once in two days will cause dehydration(me in example) So It's just the climate with no dramatization, I guess?? (My apologies if the english improper)
Lol.. I can't help but snort everytime in most BL manga that dramatize the effect of rain. Like 'why were you staggering in the rain wearing light clothes' or 'you will catch a cold'.. Or in other manga when they are drenched in the rain and then... 'Lets go to a love hotel!' or 'Let me go to your house'..
For me and most of the people in my region, when we are children, raining means.. 'Let's go outside and play!!!' Even it is very often people will get drenched because we never pay attention on weather forecast and simply forgot to bring umbrella or raincoat.. And when the rain drizzles sometimes we wont even bother wearing umbrella.. My high school even more hardcore than ever.. When it is raining, we even keep the ceremony going on (we have to stand in the school yard while the principal will talk about this or that)!!!
So.. Seeing that kind of cliche in yaoi manga is just too funny I can't even get emotional about it. Anyway.. Sorry for the rambling..