Tamago sando is a soft and creamy egg sandwich made with shokupan, hard-boiled eggs, and Kewpie mayonnaise.
Storing egg salad: Put the egg salad in an airtight storage container and refrigerate for up to 3 days. For the best texture, keep the egg salad and bread separate until it’s time to serve them.
Find it online: https://pickledplum.com/japanese-egg-sandwich/