You can use cherry blossom flavor oil (and pink dye) if you can't find all the ingredients here. You can also use canned (salted or unsalted - which one do you prefer?) white beans/Cannellini beans/Navy beans that are precooked in a can - and mash them, or put them via a food processor.
https://cookpad.com/us/recipes/149974-sakura-an-paste-made-of-preserved-sakura-leaves
Type "bean paste" in Cookpad's search bar for all the "bean paste" recipes.
You can also create Edamame bean paste for "Zunda mochi" - fava/broad beans/soramame can cause life-threatening reactions in some people.
https://cookpad.com/us/recipes/169702-fava-bean-paste-or-edamame
Shiroan (white/dyed bean pastes) can be used in all kinds of confectionary. Such as these Peach Nerikiri Wagashi (Peach Balls):
Anko paste (adzuki bean paste) made with kombu, raisins, and persimmons:
https://cookpad.com/us/recipes/156109-macrobiotic-anko-sweet-adzuki-bean-paste
A basic lima bean "Koshi-an" recipe. Add flavor oils/dyes if wanted. You can use other white beans/canned white beans instead too (might want "unsalted/no salt added" canned beans).
https://cookpad.com/us/recipes/168661-shiro-koshi-an-smooth-white-sweet-bean-paste
One Piece Anime Nerikiri you can easily DIY:
https://cookpad.com/us/recipes/151652-one-piece-nerikiri-rice-dough-sweet-bean-paste-snacks
Anpanman cupcakes (with Nerikiri character faces):
https://cookpad.com/us/recipes/151692-anpanman-cupcakes
You can use homemade bean pastes/Shiroan/Anko (or any bean paste color/flavor you want) on homemade Mitarashi Dango:
https://cookpad.com/us/recipes/149982-mitarashi-dango-for-cherry-blossom-viewing-parties
Mizu-Yokan you can make at home (this one uses Mango):
https://cookpad.com/us/recipes/149254-mango-mizu-yokan-soft-adzuki-bean-jelly
Have you tried/made anything with bean pastes yet?