365 Happy Days! is a Weiß Schwarz card from Love Live! DX Vol.2 LL/EN-W02-E144. Compare listings from Singapore Weiß Schwarz sellers on CardJio, then jio them on WhatsApp.
If the number of 《Music》 characters you have is two or less, this card cannot be played from your hand. Choose one of your opponent's cost 1 or less characters, and put it on the bottom of his or her deck. Put this card into your memory.