Happinet released the 2nd Nintendo 3DS theme collection of the 12 Sai: Koisuru Diary in the Japan Nintendo eShop.
You can buy each of them for 200 Yen (with tax) or you can get all the 3 in one package for 500 Yen (with tax). The theme collection includes themes based on the latest version of the Nintendo 3DS 12 Sai game with normal wallpapers on the top screen and moving ones on the bottom screen and with BGM.

To celebrate of the Valentine’s Day, you can download free 12 Sai Valentine’s Day PC wallpapers until March from the official website.