Return overnight bus ticket

I plan to take overnight bus from Osaka to Toyama and overnight bus from Toyama to Kyoto.

I discovered if we buy return ticket between Osaka and Toyama, it cost much cheaper than you buy one way from Osaka to Toyama, and one way from Toyama to Kyoto. My question is, can I buy return ticket between Osaka and Toyama, but then get off at Kyoto, since it's one of the stop before Osaka? Will the driver allow this kind of situation?