I found out about it through @alfalfa147!
https://oshinoko-community.com/posts/fb8de633-180f-4b1b-bf6b-6e2a9cc77b92
I heard it's already on sale, so I ordered it right away.
I wonder what kind of sweets they'll have this time?<img src="https://storage.googleapis.com/oshinoko-5xfoy/oshinoko-5xfoy/admin-console-images/1733828366861_463cf54e-9954-49a5-90c5-5128f06f7d78.png" alt="" height="28" width="28" fetchpriority="high" class="mx-2 mt-2 inline-block align-bottom">

[Oshi no Ko] x River Steam | つちのこ@苺プロ_サポーター's post