Stomachs on legs are proud to present

I've already documented my devotion to heavenly Japanese sponge cakes. I didn't think it could get any better - but it just did.

We had colleagues (or should I say 'alcoholleagues') visit from Japan, and they brought with them a bottle of sake and this wonderful alcohol-infused sponge as souvenirs. How could the sponge retain that dense, yet very fine and soft melt-in-your-mouth texture while stored indefinitely in foil, stewing in its own tipsy juices?

The taste was, like any good castella: lovely, light and a little eggy, with only a yeasty hint of methylated spirits from the booze.
(Note: I think the soaking alcohol may have been shochu, but would love if Nalika can provide insight here).

Each square of this palm-sized cake really packed a punch. I wish there was a way to mail-order it from Japan.