Episode 13
Toshio Suzuki and Studio Ghibli produced the short to commemorate the 15th anniversary of the Taiko no Tatsujin (Taiko: Drum Master) rhythm game series. The short features Taiko no Tatsujin characters Don-chan and Kacchan, as well as an original mouse character. The short will also be broadcast as a TV ad later. (Source: Anime News Network)
EP 13 - Episode 13

2015
Taiko no Tatsujin: 15 Shuunen Kinen Short Animation
Toshio Suzuki and Studio Ghibli produced the short to commemorate the 15th anniversary of the Taiko no Tatsujin (Taiko: Drum Master) rhythm game series. The short features Taiko no Tatsujin characters Don-chan and Kacchan, as well as an original mouse character. The short will also be broadcast as a TV ad later.
(Source: Anime News Network)