Diwrnod Mawr y Ddau Jac

Jac y Jwc has come around to look after Jac Do while Sali Mali takes a walk with a friend. But Jac Do is worried. Jac y Jwc doesn't know what cup is Jac Do's favourite cup, or what his favourite lunch is, or where his toys are kept! Can Jac Do put his worries aside and have fun with Jac y Jwc?