Which airline are you arriving on? Oversize items often take 15 to 30 min longer to arrive than regular baggage, but it varies by airline and aircraft type. Rarely is it possible to meet MCT with a snowboard, also there is an increased chance of secondary customs inspection with that item. Tight connections aren't a great idea at NRT where the on-time arrival record is spotty for most flights to start with, might have been better to route via ICN for that.