'Motoyama' is one of the good Restaurants of 'Kobe Beef' in Tokyo.
Kobe Steak Gyuan would be the good candidate. https://s.tabelog.com/tokyo/A1301/A130101/13002336/?lid=header_restaurant_detail_party_lst
It's a restaurant whoes owner is from Kobe and started the restaurant 30 years ago. During lunch time, you can have steak only for 1000yen. Be careful they're closed on Sundays and holidays.