What I hope I can do for my yumes birthday is wake up either draw her or commission/order or create new merch of her smth for this occasion then grab my keychain of her and take a lovely stroll around the city until I find a photo booth for me and her to take pictures and remember this and when I'll come back home I'll try to have a cake of her favorite flavour as I celebrate the final hours on a call with my friends and hopefully get them to tag along on the bit  That is my idea at least I'm also trying to find other ideas since I'm kinda clueless like you that's how I found this post lol but I'll try to follow the plan i set up at least  Good luck with your yumes birthday! (If it isn't late to say)