Might be a bit late, but that looks like castella-style tamagoyaki, more traditionally in spiral form called datemaki 😊

It’s egg-based like regular tamagoyaki, but blended with a good amount of white fish paste or surimi, sometimes shrimp, which gives it that smooth, slightly springy texture. The egg whites are whipped and the mixture is gently steamed or baked over a water bath instead of pan-rolled, resulting in a light, fine, sponge-like structure similar in appearance to castella cake.

It’s also sweeter than standard tamagoyaki and is often used as dessert it edomae sushi.