Tsumami at Yorozu included hotaru ika aged over a week in its own guts, 17-day aged mirugai (🤯), sawara aged in sake-kasu for more than 3 weeks, and aori ika that had been rested in salt and ginger. The textures were incredibly soft, but there were no "off" or "funky" flavors.
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Heck, even the slice of young potato had been aged over a few weeks so that it was pleasantly crunchy and soft, like a prototype salt-and-vinegar potato chip.