Oshogatsu

 is the thirty-first album released by Seifuku Koujo Iinkai. Released after their disbandment, the album featured various sub-units under the SKi Family, and was originally credited as "Hoshikawa Ririka and SKi" (星川りりか&SKi). However, digital releases of the album use the Seifuku Koujo Iinkai name instead, and the album is officially credited as the group's thirty-first.

Tracklist

 * 1) Miso Nippon (味噌ニッポン; Miso Japan) (Kotobuki Tai)
 * 2) Colour (カラー) (SKi)
 * 3) Shiranai Mama ni (知らないままに; Without knowing it) (SKi)
 * 4) I'm Free (Katahira Hinako)
 * 5) Cutie Cat (Hellow)
 * 6) Kinenbi (記念日; Anniversary) (Hellow)
 * 7) Nippon (ニッポン; Japan) (THE DUET)
 * 8) Itsudemo Koko de... (いつでもここで．．．; Always here...) (SKi)
 * 9) Oshogatsu (お正月; New Year's Day) (SKi)
 * 10) Oshogatsu (Karaoke)
 * 11) Itsudemo Koko de... (Karaoke)

Featured Artists

 * SKi
 * Hashimoto Mika
 * Mitsuo Mafuyu
 * Hoshikawa Ririka
 * Katahira Hinako
 * Kotobuki Tai
 * Katahira Hinako
 * Sato Honami


 * Hellow
 * Hoshikawa Ririka
 * Hashimoto Mika


 * THE DUET
 * Mitsuo Mafuyu
 * Hashimoto Mika