This is DLC you can play in Taiko Mode.

*Song: "Garasu Wo Ware"
Easy: ★3 Normal: ★4 Hard: ★4 Extreme: ★6

*Song: "SYNCHRONICITY"
Easy: ★2 Normal: ★3 Hard: ★5 Extreme: ★7

*Song: "Koisuru Fortune Cookie"
Easy: ★3 Normal: ★4 Hard: ★6 Extreme: ★7

More details on the official game page of Taiko no Tatsujin: Drum 'n' Fun! Pops Pack Vol. 2 ...