To go limited 500 yen! You can buy "Kaisendon" & "Butadon" at Ginji, a connoisseur.
To go limited menus "One Coin", "Seafood Bowl" and "Butadon" are on sale at some of the izakaya "Ginji of Connoisseurs", "Yokohama Uoman" and "Hamayaki Hokkaido Uoman".