"Maji Desu ka Ska!" (まじですかスカ!,Maji Desu ka Suka!?, Seriously, Ska!?) is the 45th single of the Japanese group Morning Musume, released on April 6, 2011 on the Zetima record label. The single sold 33,698 copies in its first week, charting at #5 on the weekly Oricon singles charts and peaking at #7 on the Japan Billboard Hot 100.
The single was released in five versions, the first single by the group to be released in more than four types: a regular edition, and four limited editions (A, B, C and D) all including a different DVD. Each DVD contains a solo interview with a member of the ninth generation. All limited editions and the first press of the regular edition sport different covers and contain a serial number card, which could be used to enter a draw to win release event tickets.
On February 23, 2011, Bijo Gaku, Hello! Project's weekly variety show, aired the first preview of the song. The following day an official preview was aired on radio.
Upon its release, the single was the group's 45th consecutive top-10 single, with all releases since "Morning Coffee" having charted within the top 10 on the Oricon charts. This feat equaled SMAP's record of 45 consecutive top 10-charting singles, whose 45th single, "This is Love", was released in August 2010.