sure thing.
lolitas and cosplay fans are young teenagers who dress up in in all sorts of interesting outfits ranging in themes from Nazis to horror/french maids... usually in relation to characters from video games or anime.
they usually just hang out together on a sunday afternoon in Harajuku.
here is a site with photos
http://www.photosaga.com/Japon%20kids/
some people call them freaks, but i think its a bit rude since they are actually mostly really sweet school children just having fun.
Kujira is whale meat, Natto is a sticky bean substance, Roppongi is an area in Tokyo with heaps of night clubs, strip clubs, hostess bars and the like... its usually despised by most people because its a mecca for drunk westerners like marines and english teachers.
yes, its bad manners to talk on your phone on the train... although many people do. but a friend of mine was shouted at by an elderly man (oyaji) when he used his, so i refrain.
old men 'harassing' foreigners isn't really a cultural thing. i've been latched onto countless times... sometimes they just want to practice speaking english, some want money and think westerners are soft touches, some just want to interact.
yes, women are molested in trains and it is a serious problem. so far there are only women-only train cars in kyoto... but they will be in the main lines in tokyo soon. the subway/metro is the worst for molestation since it is always seriously packed and hentai (perverts) are often concealed in the mass. the other problem here is that 90% of japanese women are far too concerned with not causing a scene... and as a result they don't yell out when perverts grope them.