I find that with a good rig and higher-poly models, #1 is superior. It allows and encourages much more believable muscle behaviour when deforming, instead of just "deforming" like a tube. Though if simply keeping general volume and ease of setup is the goal, then #2. I know this thread was dead, but the discussion on…
actually, i've seen the variant in the lower picture more often in production models than the one from above (which i'd use and recommend myself). i don't think it's a japanese thing, more of a "traditional" way of modelling them, used by a majority of artists, including many leads who usually create the initial assets…