Sorry to say this but while you suffer from the heat and humidity in Singapore/Malaysia and elsewhere, the weather in Tokyo is perfect for travelling with day time temperature of about 19 celcius! Even though I undertake marathon treks in this urban jungle, I never feel tired.
Tokyo is a food paradise for those who live to eat. There are cute little eateries in abundance. The only downside is that I have to pay double for the sort of Japanese food I get in Singapore.