15 Thank You, Too (stylized as ⑮ Thank you, too) is the 15th studio album by the Japanese girl group Morning Musume '17.

The album was announced on October 21[1] in Hokkaido, during their 2017 Autumn Tour: "Morning Musume Tanjō 20 Shuunen Kinen Concert Tour 2017 Aki ~We are MORNING MUSUME~".

On November 2, the official track list was released and revealed that only their two most recent singles were included.

This release also includes a limited edition Blu-ray recording of their 20th Anniversary Event held on September 14, 2017 in Shinkiba Studio Coast: "Morning Musume Kessei 20 Shuunen Kinen Event ~21 Nenme mo Ganbatte Ikimasshoi!~".

The event featured surprise guests, Sayumi Michishige and Reina Tanaka (Morning Musume OG).