Vietnam Airlines from Singapore to Tokyo has 6 flights every day. And there are 42 flights per week flying out of Singapore which connect to Tokyo.
The price for economy class – one way ticket of Vietnam Airlines from Singapore to Tokyo is 34.727.000 VND (or ~$1734 USD) and the price for bussiness class – one way ticket of Vietnam Airline is 49.255.000 VND (or ~$2461 USD).