as you know already, most shellfish show sweet nutty characters when served raw....and few (like the butter clams in the Pc NW, and the "beach chesnut" clam known as the hamaguri here in Jp) do well with a quick white wine simmer, then add a butter lemon dip and a romorantin and you go to heaven.
the hokkigai prob gets it's name from being a hokkaido clam (just a guess...i haven't seen the kanji yet) but i just saw a photo online. yep we get that here, but the prob is, it's literally so removed from its place (not to mention it's shell) that one ends up with something which might work better as a chopstick holder than a delicacy. they might brine it, but what's the need to do so....? i think you pop the shell and slice and dice, with some shoyu and wasabi on hand and then judge for yourself which way you want to go, Joe.