Even though the railroad cars being used are Japan National Railways' (JNR) 381 series limited express cars (old JNR cars that belong to the Hineno Train Depot), the "Yamatoji Liner" is a rapid train rather than a limited express, meaning that you can use a Seishun 18 ticket (a discount rail ticket) provided you have purchased a numbered boarding ticket.
車両は特急形車両の国鉄381系電車（日根野電車区所属の旧国鉄色編成）が使用されるが、「やまとじライナー」の種別は特急ではなく快速であるため、乗車整理券を購入さえすれば青春18きっぷでも利用できる。