Obana-san was one of the earliest supporters of Yamayuki as a line-caught tuna wholesaler and thus (supposedly) has preferred access for maguro. He usually favors smaller-size tuna and only ages a couple of days at most. On all of my visits, cuts from two different fish, usually from different landing points have been served. The only change I've noticed over the years is that the "chu-maki" made from the tender tuna scrapings appears now as an appetizer rather than a finale.